diff --git a/.gitignore b/.gitignore
index 34a8640e70..919ec9d49d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,3 +42,6 @@ storybook-static
 # vitepress
 /docs/.vitepress/dist
 /docs/.vitepress/cache
+
+# Local Netlify folder
+.netlify
diff --git a/apps/web/src/settings/Settings.tsx b/apps/web/src/settings/Settings.tsx
index b027283610..c613a73ce0 100644
--- a/apps/web/src/settings/Settings.tsx
+++ b/apps/web/src/settings/Settings.tsx
@@ -368,8 +368,8 @@ export interface Settings {
     "inviteRules": IBaseSetting<ComputedInviteConfig>;
     "blockInvites": IBaseSetting<boolean>;
     "Developer.elementCallUrl": IBaseSetting<string>;
-    "RoomList.CustomSectionData": IBaseSetting<CustomSectionsData>;
-    "RoomList.OrderedCustomSections": IBaseSetting<OrderedCustomSections>;
+    "element.io.prototype.RoomList.CustomSectionData": IBaseSetting<CustomSectionsData>;
+    "element.io.prototype.RoomList.OrderedCustomSections": IBaseSetting<OrderedCustomSections>;
 }
 
 export type SettingKey = keyof Settings;
@@ -1379,7 +1379,7 @@ export const SETTINGS: Settings = {
      * Managed by the {@link RoomListStoreV3}
      * Store the custom section data for the room list
      */
-    "RoomList.CustomSectionData": {
+    "element.io.prototype.RoomList.CustomSectionData": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         default: {},
     },
@@ -1387,7 +1387,7 @@ export const SETTINGS: Settings = {
      * Managed by the {@link RoomListStoreV3}
      * Store the ordering of the custom sections for the room list, keyed by space/metaspace ID.
      */
-    "RoomList.OrderedCustomSections": {
+    "element.io.prototype.RoomList.OrderedCustomSections": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
         default: {},
     },
diff --git a/apps/web/src/stores/room-list-v3/RoomListStoreV3.ts b/apps/web/src/stores/room-list-v3/RoomListStoreV3.ts
index 0516826807..b20c4af2e1 100644
--- a/apps/web/src/stores/room-list-v3/RoomListStoreV3.ts
+++ b/apps/web/src/stores/room-list-v3/RoomListStoreV3.ts
@@ -133,7 +133,7 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
             this.onActiveSpaceChanged();
         });
         SpaceStore.instance.on(UPDATE_HOME_BEHAVIOUR, () => this.onActiveSpaceChanged());
-        SettingsStore.watchSetting("RoomList.OrderedCustomSections", null, () => this.onOrderedCustomSectionsChange());
+        SettingsStore.watchSetting("element.io.prototype.RoomList.OrderedCustomSections", null, () => this.onOrderedCustomSectionsChange());
         this.loadCustomSections();
     }
 
@@ -532,7 +532,10 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
      */
     private loadCustomSections(): void {
         const activeSpace = SpaceStore.instance.activeSpace;
-        const orderedCustomSections: Record<string, string[]> = SettingsStore.getValue("RoomList.OrderedCustomSections") || {};
+        const storedSections = SettingsStore.getValue("element.io.prototype.RoomList.OrderedCustomSections");
+        // Guard against legacy flat-array format stored by the base branch
+        const orderedCustomSections: Record<string, string[]> =
+            storedSections && !Array.isArray(storedSections) ? storedSections : {};
         const spaceSections = orderedCustomSections[activeSpace] ?? [];
         this.sortedTags = [DefaultTagID.Favourite, ...spaceSections, CHATS_TAG, DefaultTagID.LowPriority];
     }
diff --git a/apps/web/src/stores/room-list-v3/section.ts b/apps/web/src/stores/room-list-v3/section.ts
index 785884cf18..040b00bf07 100644
--- a/apps/web/src/stores/room-list-v3/section.ts
+++ b/apps/web/src/stores/room-list-v3/section.ts
@@ -65,17 +65,18 @@ export async function createSection(spaceId: SpaceKey): Promise<string | undefin
     const tag = `${CUSTOM_SECTION_TAG_PREFIX}${window.crypto.randomUUID()}`;
     const newSection: CustomSection = { tag, name: sectionName, spaceId };
 
-    // Save the new section data
-    const sectionData = SettingsStore.getValue("RoomList.CustomSectionData") || {};
+    // Save the new section data — shallow-copy to avoid mutating the settings cache reference
+    const sectionData = { ...(SettingsStore.getValue("element.io.prototype.RoomList.CustomSectionData") || {}) };
     sectionData[tag] = newSection;
-    await SettingsStore.setValue("RoomList.CustomSectionData", null, SettingLevel.ACCOUNT, sectionData);
+    await SettingsStore.setValue("element.io.prototype.RoomList.CustomSectionData", null, SettingLevel.ACCOUNT, sectionData);
 
     // Add the new section to the ordered list of sections for this space
-    const orderedSections: OrderedCustomSections = SettingsStore.getValue("RoomList.OrderedCustomSections") || {};
-    const spaceSections = orderedSections[spaceId] ?? [];
-    spaceSections.push(tag);
-    orderedSections[spaceId] = spaceSections;
-    await SettingsStore.setValue("RoomList.OrderedCustomSections", null, SettingLevel.ACCOUNT, orderedSections);
+    // Shallow-copy and guard against legacy flat-array format from the base branch
+    const storedSections = SettingsStore.getValue("element.io.prototype.RoomList.OrderedCustomSections");
+    const orderedSections: OrderedCustomSections =
+        storedSections && !Array.isArray(storedSections) ? { ...storedSections } : {};
+    orderedSections[spaceId] = [...(orderedSections[spaceId] ?? []), tag];
+    await SettingsStore.setValue("element.io.prototype.RoomList.OrderedCustomSections", null, SettingLevel.ACCOUNT, orderedSections);
     return tag;
 }
 
@@ -84,7 +85,7 @@ export async function createSection(spaceId: SpaceKey): Promise<string | undefin
  * @param tag - The tag of the section to edit.
  */
 export async function editSection(tag: string): Promise<void> {
-    const sectionData = SettingsStore.getValue("RoomList.CustomSectionData") || {};
+    const sectionData = SettingsStore.getValue("element.io.prototype.RoomList.CustomSectionData") || {};
     const section = sectionData[tag];
     if (!section) {
         logger.info("Unknown section tag, cannot edit section", tag);
@@ -99,7 +100,7 @@ export async function editSection(tag: string): Promise<void> {
 
     // Save the new name
     sectionData[tag].name = newName;
-    await SettingsStore.setValue("RoomList.CustomSectionData", null, SettingLevel.ACCOUNT, sectionData);
+    await SettingsStore.setValue("element.io.prototype.RoomList.CustomSectionData", null, SettingLevel.ACCOUNT, sectionData);
 }
 
 /**
@@ -108,7 +109,7 @@ export async function editSection(tag: string): Promise<void> {
  * @param isEmpty - Whether the section is empty (has no rooms). If the section is not empty, the confirmation dialog will show a warning message.
  */
 export async function deleteSection(tag: string, isEmpty: boolean): Promise<void> {
-    const sectionData = SettingsStore.getValue("RoomList.CustomSectionData");
+    const sectionData = SettingsStore.getValue("element.io.prototype.RoomList.CustomSectionData");
     if (!sectionData[tag]) {
         logger.info("Unknown section tag, cannot delete section", tag);
         return;
@@ -120,13 +121,16 @@ export async function deleteSection(tag: string, isEmpty: boolean): Promise<void
 
     // Remove the section from the ordered list of sections for its space
     const spaceId = sectionData[tag].spaceId;
-    const orderedSections: OrderedCustomSections = SettingsStore.getValue("RoomList.OrderedCustomSections") || {};
+    const storedSections = SettingsStore.getValue("element.io.prototype.RoomList.OrderedCustomSections");
+    const orderedSections: OrderedCustomSections =
+        storedSections && !Array.isArray(storedSections) ? { ...storedSections } : {};
     if (orderedSections[spaceId]) {
         orderedSections[spaceId] = orderedSections[spaceId].filter((sectionTag) => sectionTag !== tag);
     }
-    await SettingsStore.setValue("RoomList.OrderedCustomSections", null, SettingLevel.ACCOUNT, orderedSections);
+    await SettingsStore.setValue("element.io.prototype.RoomList.OrderedCustomSections", null, SettingLevel.ACCOUNT, orderedSections);
 
-    // Remove the section data
-    delete sectionData[tag];
-    await SettingsStore.setValue("RoomList.CustomSectionData", null, SettingLevel.ACCOUNT, sectionData);
+    // Remove the section data — shallow-copy to avoid mutating the settings cache reference
+    const updatedSectionData = { ...sectionData };
+    delete updatedSectionData[tag];
+    await SettingsStore.setValue("element.io.prototype.RoomList.CustomSectionData", null, SettingLevel.ACCOUNT, updatedSectionData);
 }
diff --git a/apps/web/src/utils/room/tagRoom.ts b/apps/web/src/utils/room/tagRoom.ts
index 62bac2ffca..f9262865f5 100644
--- a/apps/web/src/utils/room/tagRoom.ts
+++ b/apps/web/src/utils/room/tagRoom.ts
@@ -14,13 +14,17 @@ import RoomListActions from "../../actions/RoomListActions";
 import dis from "../../dispatcher/dispatcher";
 import { getTagsForRoom } from "./getTagsForRoom";
 import { isCustomSectionTag } from "../../stores/room-list-v3/section";
+import RoomListStoreV3 from "../../stores/room-list-v3/RoomListStoreV3";
 
 /**
  * Toggle tag for a given room.
- * A room can only be in one section: either a custom section, Favourite, or LowPriority.
- * Applying any of these will atomically replace the current section tag.
+ *
+ * - For custom section tags: replaces the active space's current custom section tag (if any),
+ *   leaving tags from other spaces intact. A room can be in one custom section per space.
+ * - For Favourite/LowPriority: simple toggle of that specific tag, independent of custom sections.
+ *
  * @param room The room to tag
- * @param tagId The tag to invert
+ * @param tagId The tag to toggle
  */
 export function tagRoom(room: Room, tagId: TagID): void {
     if (tagId !== DefaultTagID.Favourite && tagId !== DefaultTagID.LowPriority && !isCustomSectionTag(tagId)) {
@@ -28,14 +32,25 @@ export function tagRoom(room: Room, tagId: TagID): void {
         return;
     }
 
-    // Find the section tag currently applied (Fav, LowPriority, or custom) — at most one exists
-    const currentSectionTag =
-        getTagsForRoom(room).find(
-            (t) => t === DefaultTagID.Favourite || t === DefaultTagID.LowPriority || isCustomSectionTag(t),
-        ) ?? null;
+    let removeTag: TagID | null;
+    let addTag: TagID | null;
+
+    if (isCustomSectionTag(tagId)) {
+        // For custom sections: only replace within the active space's custom sections.
+        // Tags from other spaces are left intact.
+        const activeSpaceCustomSectionTags = new Set(
+            RoomListStoreV3.instance.orderedSectionTags.filter((t) => isCustomSectionTag(t)),
+        );
+        const currentSectionTag = getTagsForRoom(room).find((t) => activeSpaceCustomSectionTags.has(t)) ?? null;
+        const isApplied = currentSectionTag === tagId;
+        removeTag = currentSectionTag;
+        addTag = isApplied ? null : tagId;
+    } else {
+        // For Favourite/LowPriority: simple toggle — independent of custom sections.
+        const isApplied = getTagsForRoom(room).includes(tagId);
+        removeTag = isApplied ? tagId : null;
+        addTag = isApplied ? null : tagId;
+    }
 
-    const isApplied = currentSectionTag === tagId;
-    const removeTag = currentSectionTag;
-    const addTag = isApplied ? null : tagId;
     dis.dispatch(RoomListActions.tagRoom(room.client, room, removeTag, addTag));
 }
diff --git a/apps/web/src/viewmodels/room-list/RoomListItemViewModel.ts b/apps/web/src/viewmodels/room-list/RoomListItemViewModel.ts
index b247ade51c..eca3de0191 100644
--- a/apps/web/src/viewmodels/room-list/RoomListItemViewModel.ts
+++ b/apps/web/src/viewmodels/room-list/RoomListItemViewModel.ts
@@ -38,7 +38,7 @@ import { Action } from "../../dispatcher/actions";
 import type { ViewRoomPayload } from "../../dispatcher/payloads/ViewRoomPayload";
 import PosthogTrackers from "../../PosthogTrackers";
 import { type Call, CallEvent } from "../../models/Call";
-import RoomListStoreV3, { CHATS_TAG } from "../../stores/room-list-v3/RoomListStoreV3";
+import RoomListStoreV3, { CHATS_TAG, LISTS_UPDATE_EVENT } from "../../stores/room-list-v3/RoomListStoreV3";
 import { _t } from "../../languageHandler";
 
 interface RoomItemProps {
@@ -98,13 +98,18 @@ export class RoomListItemViewModel
         this.disposables.trackListener(props.room, RoomEvent.Name, this.onRoomChanged);
         this.disposables.trackListener(props.room, RoomEvent.Tags, this.onRoomChanged);
 
-        const orderSectionsRef = SettingsStore.watchSetting("RoomList.OrderedCustomSections", null, () =>
+        const orderSectionsRef = SettingsStore.watchSetting("element.io.prototype.RoomList.OrderedCustomSections", null, () =>
             this.onOrderedCustomSectionsChange(),
         );
         this.disposables.track(() => {
             SettingsStore.unwatchSetting(orderSectionsRef);
         });
 
+        // Rebuild sections when the active space changes (variant-a: sections are scoped per space).
+        // Listen to LISTS_UPDATE_EVENT (not UPDATE_SELECTED_SPACE directly) to guarantee that
+        // RoomListStoreV3 has already called loadCustomSections() and updated orderedSectionTags.
+        this.disposables.trackListener(RoomListStoreV3.instance, LISTS_UPDATE_EVENT, this.onOrderedCustomSectionsChange);
+
         // Load message preview asynchronously (sync data is already complete)
         void this.loadAndSetMessagePreview();
     }
@@ -423,7 +428,7 @@ export class RoomListItemViewModel
      * Order follows the canonical section order from RoomListStoreV3.
      */
     private static buildSections(roomTags: Room["tags"]): Section[] {
-        const customSectionData = SettingsStore.getValue("RoomList.CustomSectionData") || {};
+        const customSectionData = SettingsStore.getValue("element.io.prototype.RoomList.CustomSectionData") || {};
 
         return (
             RoomListStoreV3.instance.orderedSectionTags
diff --git a/apps/web/src/viewmodels/room-list/RoomListSectionHeaderViewModel.ts b/apps/web/src/viewmodels/room-list/RoomListSectionHeaderViewModel.ts
index a7b8d6dd2d..7008951850 100644
--- a/apps/web/src/viewmodels/room-list/RoomListSectionHeaderViewModel.ts
+++ b/apps/web/src/viewmodels/room-list/RoomListSectionHeaderViewModel.ts
@@ -54,7 +54,7 @@ export class RoomListSectionHeaderViewModel
             isUnread: false,
             displaySectionMenu: !isDefaultSection,
         });
-        const sectionWatherRef = SettingsStore.watchSetting("RoomList.CustomSectionData", null, () =>
+        const sectionWatherRef = SettingsStore.watchSetting("element.io.prototype.RoomList.CustomSectionData", null, () =>
             this.onCustomSectionDataChange(),
         );
         this.disposables.track(() => SettingsStore.unwatchSetting(sectionWatherRef));
@@ -140,7 +140,7 @@ export class RoomListSectionHeaderViewModel
      * Handle changes to custom section data.
      */
     private onCustomSectionDataChange(): void {
-        const customSectionData = SettingsStore.getValue("RoomList.CustomSectionData") || {};
+        const customSectionData = SettingsStore.getValue("element.io.prototype.RoomList.CustomSectionData") || {};
         const sectionData = customSectionData[this.props.tag];
         if (sectionData) {
             this.snapshot.merge({ title: sectionData.name });
diff --git a/apps/web/src/viewmodels/room-list/RoomListViewModel.ts b/apps/web/src/viewmodels/room-list/RoomListViewModel.ts
index e711e340b0..40dd3bc5df 100644
--- a/apps/web/src/viewmodels/room-list/RoomListViewModel.ts
+++ b/apps/web/src/viewmodels/room-list/RoomListViewModel.ts
@@ -284,7 +284,7 @@ export class RoomListViewModel
     public getSectionHeaderViewModel(tag: string): RoomListSectionHeaderViewModel {
         if (this.roomSectionHeaderViewModels.has(tag)) return this.roomSectionHeaderViewModels.get(tag)!;
 
-        const customSections = SettingsStore.getValue("RoomList.CustomSectionData");
+        const customSections = SettingsStore.getValue("element.io.prototype.RoomList.CustomSectionData");
         const title = TAG_TO_TITLE_MAP[tag] || customSections[tag]?.name || tag;
         const viewModel = new RoomListSectionHeaderViewModel({
             tag,
@@ -637,7 +637,7 @@ function computeSections(
     roomsResult: RoomsResult,
     isSectionExpanded: (tag: string) => boolean,
 ): { sections: Section[]; isFlatList: boolean } {
-    const customSections = SettingsStore.getValue("RoomList.CustomSectionData");
+    const customSections = SettingsStore.getValue("element.io.prototype.RoomList.CustomSectionData");
 
     const sections = roomsResult.sections
         // Only include sections that have rooms or are custom sections (which may be empty but should still be shown)
diff --git a/apps/web/test/unit-tests/stores/room-list-v3/RoomListStoreV3-test.ts b/apps/web/test/unit-tests/stores/room-list-v3/RoomListStoreV3-test.ts
index fa3def1e46..5561403387 100644
--- a/apps/web/test/unit-tests/stores/room-list-v3/RoomListStoreV3-test.ts
+++ b/apps/web/test/unit-tests/stores/room-list-v3/RoomListStoreV3-test.ts
@@ -832,7 +832,7 @@ describe("RoomListStoreV3", () => {
         function enableSections(): void {
             jest.spyOn(SettingsStore, "getValue").mockImplementation((setting: string) => {
                 if (setting === "feature_room_list_sections") return true;
-                if (setting === "RoomList.OrderedCustomSections") return [];
+                if (setting === "element.io.prototype.RoomList.OrderedCustomSections") return {};
                 return false;
             });
         }
@@ -1084,7 +1084,8 @@ describe("RoomListStoreV3", () => {
 
             let settingsWatcher: (settingName: string) => void = () => {};
             jest.spyOn(SettingsStore, "watchSetting").mockImplementation((settingName, _roomId, callback) => {
-                if (settingName === "RoomList.OrderedCustomSections") settingsWatcher = callback as () => void;
+                if (settingName === "element.io.prototype.RoomList.OrderedCustomSections")
+                    settingsWatcher = callback as () => void;
                 return "watcher-id";
             });
 
@@ -1092,7 +1093,7 @@ describe("RoomListStoreV3", () => {
 
             jest.spyOn(SettingsStore, "getValue").mockImplementation((setting: string) => {
                 if (setting === "feature_room_list_sections") return true;
-                if (setting === "RoomList.OrderedCustomSections") return [];
+                if (setting === "element.io.prototype.RoomList.OrderedCustomSections") return {};
                 return false;
             });
 
@@ -1106,12 +1107,13 @@ describe("RoomListStoreV3", () => {
             rooms[0].tags = { [customTag]: { order: 0 } };
             jest.spyOn(SettingsStore, "getValue").mockImplementation((setting: string) => {
                 if (setting === "feature_room_list_sections") return true;
-                if (setting === "RoomList.OrderedCustomSections") return [customTag];
+                if (setting === "element.io.prototype.RoomList.OrderedCustomSections")
+                    return { [MetaSpace.Home]: [customTag] };
                 return false;
             });
 
             // Trigger the settings watcher
-            settingsWatcher("RoomList.OrderedCustomSections");
+            settingsWatcher("element.io.prototype.RoomList.OrderedCustomSections");
 
             // Now there should be 4 sections (Favourite, custom, Chats, LowPriority)
             expect(store.getSortedRoomsInActiveSpace().sections).toHaveLength(4);
diff --git a/apps/web/test/unit-tests/stores/room-list-v3/section-test.ts b/apps/web/test/unit-tests/stores/room-list-v3/section-test.ts
index bfb999871e..e2543d9ce0 100644
--- a/apps/web/test/unit-tests/stores/room-list-v3/section-test.ts
+++ b/apps/web/test/unit-tests/stores/room-list-v3/section-test.ts
@@ -10,6 +10,7 @@ import SettingsStore from "../../../../src/settings/SettingsStore";
 import { createSection, editSection, deleteSection } from "../../../../src/stores/room-list-v3/section";
 import { CreateSectionDialog } from "../../../../src/components/views/dialogs/CreateSectionDialog";
 import { RemoveSectionDialog } from "../../../../src/components/views/dialogs/RemoveSectionDialog";
+import { MetaSpace } from "../../../../src/stores/spaces";
 
 describe("section", () => {
     afterEach(() => {
@@ -23,8 +24,8 @@ describe("section", () => {
         });
 
         it.each([
-            [false, "", undefined],
-            [true, "", undefined],
+            [false, "", undefined] as const,
+            [true, "", undefined] as const,
             [true, "My Section", expect.stringMatching(/^element\.io\.section\./)],
         ])("returns %s when shouldCreate=%s and name='%s'", async (shouldCreate, name, expected) => {
             jest.spyOn(Modal, "createDialog").mockReturnValue({
@@ -32,7 +33,7 @@ describe("section", () => {
                 close: jest.fn(),
             } as any);
 
-            const result = await createSection();
+            const result = await createSection(MetaSpace.Home);
             expect(result).toEqual(expected);
         });
 
@@ -42,7 +43,7 @@ describe("section", () => {
                 close: jest.fn(),
             } as any);
 
-            const result = await createSection();
+            const result = await createSection(MetaSpace.Home);
             expect(result).toMatch(/^element\.io\.section\./);
         });
 
@@ -52,14 +53,14 @@ describe("section", () => {
                 close: jest.fn(),
             } as any);
 
-            await createSection();
+            await createSection(MetaSpace.Home);
             expect(createDialogSpy).toHaveBeenCalledWith(CreateSectionDialog);
         });
 
         it("saves section data and ordered sections at ACCOUNT level when confirmed", async () => {
             const existingTag = "element.io.section.existing";
             jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
-                if (setting === "RoomList.OrderedCustomSections") return [existingTag];
+                if (setting === "element.io.prototype.RoomList.OrderedCustomSections") return { [MetaSpace.Home]: [existingTag] };
                 return null;
             });
             jest.spyOn(Modal, "createDialog").mockReturnValue({
@@ -68,23 +69,29 @@ describe("section", () => {
             } as any);
             const setValueSpy = jest.spyOn(SettingsStore, "setValue").mockResolvedValue(undefined);
 
-            await createSection();
+            await createSection(MetaSpace.Home);
 
-            const customDataCall = setValueSpy.mock.calls.find(([name]) => name === "RoomList.CustomSectionData");
-            const savedSection = Object.values(customDataCall![3] as Record<string, { tag: string; name: string }>)[0];
+            const customDataCall = setValueSpy.mock.calls.find(
+                ([name]) => name === "element.io.prototype.RoomList.CustomSectionData",
+            );
+            const savedSection = Object.values(
+                customDataCall![3] as Record<string, { tag: string; name: string; spaceId: string }>,
+            )[0];
             expect(savedSection.name).toBe("My Section");
             expect(savedSection.tag).toMatch(/^element\.io\.section\./);
 
-            const orderedCall = setValueSpy.mock.calls.find(([name]) => name === "RoomList.OrderedCustomSections");
-            const savedOrder = orderedCall![3] as string[];
-            expect(savedOrder[0]).toBe(existingTag);
-            expect(savedOrder[1]).toMatch(/^element\.io\.section\./);
+            const orderedCall = setValueSpy.mock.calls.find(
+                ([name]) => name === "element.io.prototype.RoomList.OrderedCustomSections",
+            );
+            const savedOrder = orderedCall![3] as Record<string, string[]>;
+            expect(savedOrder[MetaSpace.Home][0]).toBe(existingTag);
+            expect(savedOrder[MetaSpace.Home][1]).toMatch(/^element\.io\.section\./);
         });
     });
 
     describe("editSection", () => {
         const tag = "element.io.section.abc";
-        const existingSectionData = { [tag]: { tag, name: "Old Name" } };
+        const existingSectionData = { [tag]: { tag, name: "Old Name", spaceId: MetaSpace.Home } };
 
         beforeEach(() => {
             jest.spyOn(SettingsStore, "getValue").mockReturnValue(existingSectionData);
@@ -134,10 +141,10 @@ describe("section", () => {
             await editSection(tag);
 
             expect(setValueSpy).toHaveBeenCalledWith(
-                "RoomList.CustomSectionData",
+                "element.io.prototype.RoomList.CustomSectionData",
                 null,
                 expect.anything(),
-                expect.objectContaining({ [tag]: { tag, name: "New Name" } }),
+                expect.objectContaining({ [tag]: { tag, name: "New Name", spaceId: MetaSpace.Home } }),
             );
         });
     });
@@ -147,11 +154,15 @@ describe("section", () => {
         const otherTag = "element.io.section.other";
 
         beforeEach(() => {
-            jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
-                if (setting === "RoomList.CustomSectionData") return { [tag]: { tag, name: "My Section" } };
-                if (setting === "RoomList.OrderedCustomSections") return [otherTag, tag];
-                return null;
-            });
+            jest.spyOn(SettingsStore, "getValue").mockImplementation(
+                (setting): ReturnType<(typeof SettingsStore)["getValue"]> => {
+                    if (setting === "element.io.prototype.RoomList.CustomSectionData")
+                        return { [tag]: { tag, name: "My Section", spaceId: MetaSpace.Home } };
+                    if (setting === "element.io.prototype.RoomList.OrderedCustomSections")
+                        return { [MetaSpace.Home]: [otherTag, tag] };
+                    return null;
+                },
+            );
             jest.spyOn(SettingsStore, "setValue").mockResolvedValue(undefined);
         });
 
@@ -196,10 +207,14 @@ describe("section", () => {
 
             await deleteSection(tag, false);
 
-            const orderedCall = setValueSpy.mock.calls.find(([name]) => name === "RoomList.OrderedCustomSections");
-            expect(orderedCall![3]).toEqual([otherTag]);
+            const orderedCall = setValueSpy.mock.calls.find(
+                ([name]) => name === "element.io.prototype.RoomList.OrderedCustomSections",
+            );
+            expect(orderedCall![3]).toEqual({ [MetaSpace.Home]: [otherTag] });
 
-            const customDataCall = setValueSpy.mock.calls.find(([name]) => name === "RoomList.CustomSectionData");
+            const customDataCall = setValueSpy.mock.calls.find(
+                ([name]) => name === "element.io.prototype.RoomList.CustomSectionData",
+            );
             expect(customDataCall![3]).not.toHaveProperty(tag);
         });
     });
diff --git a/apps/web/test/viewmodels/room-list/RoomListItemViewModel-test.tsx b/apps/web/test/viewmodels/room-list/RoomListItemViewModel-test.tsx
index b545f316f9..d653fc3095 100644
--- a/apps/web/test/viewmodels/room-list/RoomListItemViewModel-test.tsx
+++ b/apps/web/test/viewmodels/room-list/RoomListItemViewModel-test.tsx
@@ -78,7 +78,7 @@ describe("RoomListItemViewModel", () => {
 
         jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
             if (setting === "RoomList.showMessagePreview") return false;
-            if (setting === "RoomList.OrderedCustomSections") return [];
+            if (setting === "element.io.prototype.RoomList.OrderedCustomSections") return {};
             return false;
         });
         jest.spyOn(SettingsStore, "watchSetting").mockImplementation(() => "watcher-id");
@@ -653,8 +653,8 @@ describe("RoomListItemViewModel", () => {
         it("should use custom section name from CustomSectionData", () => {
             jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
                 if (setting === "feature_room_list_sections") return true;
-                if (setting === "RoomList.CustomSectionData")
-                    return { [customTag]: { name: "My Custom Section", tag: customTag } };
+                if (setting === "element.io.prototype.RoomList.CustomSectionData")
+                    return { [customTag]: { name: "My Custom Section", tag: customTag, spaceId: "!space:server" } };
                 return false;
             });
             viewModel = new RoomListItemViewModel({ room, client: matrixClient });
@@ -666,7 +666,7 @@ describe("RoomListItemViewModel", () => {
         it("should update sections when OrderedCustomSections setting changes", () => {
             let watchCallback: CallbackFn<"RoomList.OrderedCustomSections"> = () => {};
             jest.spyOn(SettingsStore, "watchSetting").mockImplementation((setting, _room, callback) => {
-                if (setting === "RoomList.OrderedCustomSections") watchCallback = callback;
+                if (setting === "element.io.prototype.RoomList.OrderedCustomSections") watchCallback = callback;
                 return "watcher-id";
             });
             jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
@@ -683,7 +683,7 @@ describe("RoomListItemViewModel", () => {
                 CHATS_TAG,
                 DefaultTagID.LowPriority,
             ]);
-            watchCallback("RoomList.OrderedCustomSections", null, null as any, null, null);
+            watchCallback("element.io.prototype.RoomList.OrderedCustomSections", null, null as any, null, null);
 
             expect(viewModel.getSnapshot().sections.map((s) => s.tag)).toEqual([]);
         });
diff --git a/apps/web/test/viewmodels/room-list/RoomListSectionHeaderViewModel-test.ts b/apps/web/test/viewmodels/room-list/RoomListSectionHeaderViewModel-test.ts
index 000bbddd61..80e8d746ea 100644
--- a/apps/web/test/viewmodels/room-list/RoomListSectionHeaderViewModel-test.ts
+++ b/apps/web/test/viewmodels/room-list/RoomListSectionHeaderViewModel-test.ts
@@ -26,7 +26,7 @@ describe("RoomListSectionHeaderViewModel", () => {
         jest.spyOn(SettingsStore, "watchSetting").mockReturnValue("watcher-id");
         jest.spyOn(SettingsStore, "unwatchSetting").mockReturnValue(undefined);
         jest.spyOn(SettingsStore, "getValue").mockImplementation((setting) => {
-            if (setting === "RoomList.OrderedCustomSections") return [];
+            if (setting === "element.io.prototype.RoomList.OrderedCustomSections") return {};
             return null;
         });
     });
@@ -118,7 +118,7 @@ describe("RoomListSectionHeaderViewModel", () => {
 
         beforeEach(() => {
             jest.spyOn(SettingsStore, "watchSetting").mockImplementation((settingName, _roomId, callback) => {
-                if (settingName === "RoomList.CustomSectionData") watchCallback = callback as () => void;
+                if (settingName === "element.io.prototype.RoomList.CustomSectionData") watchCallback = callback as () => void;
                 return "watcher-id";
             });
         });
@@ -133,7 +133,7 @@ describe("RoomListSectionHeaderViewModel", () => {
             });
             expect(vm.getSnapshot().title).toBe("Old Title");
 
-            jest.spyOn(SettingsStore, "getValue").mockReturnValue({ [tag]: { tag, name: "New Title" } });
+            jest.spyOn(SettingsStore, "getValue").mockReturnValue({ [tag]: { tag, name: "New Title", spaceId: "!space:server" } });
             watchCallback();
 
             expect(vm.getSnapshot().title).toBe("New Title");