diff --git a/include/haproxy/quic_conn-t.h b/include/haproxy/quic_conn-t.h
index a85606ffc..6b5c6361b 100644
--- a/include/haproxy/quic_conn-t.h
+++ b/include/haproxy/quic_conn-t.h
@@ -432,7 +432,7 @@ struct quic_conn_closed {
 #define QUIC_FL_CONN_NEED_POST_HANDSHAKE_FRMS    (1U << 2) /* HANDSHAKE_DONE must be sent */
 #define QUIC_FL_CONN_LISTENER                    (1U << 3)
 #define QUIC_FL_CONN_ACCEPT_REGISTERED           (1U << 4)
-#define QUIC_FL_CONN_TX_MUX_CONTEXT              (1U << 5) /* sending in progress from the MUX layer */
+/* gap here */
 #define QUIC_FL_CONN_IDLE_TIMER_RESTARTED_AFTER_READ (1U << 6)
 #define QUIC_FL_CONN_RETRANS_NEEDED              (1U << 7)
 #define QUIC_FL_CONN_RETRANS_OLD_DATA            (1U << 8) /* retransmission in progress for probing with already sent data */
@@ -472,7 +472,6 @@ static forceinline char *qc_show_flags(char *buf, size_t len, const char *delim,
 	_(QUIC_FL_CONN_NEED_POST_HANDSHAKE_FRMS,
 	_(QUIC_FL_CONN_LISTENER,
 	_(QUIC_FL_CONN_ACCEPT_REGISTERED,
-	_(QUIC_FL_CONN_TX_MUX_CONTEXT,
 	_(QUIC_FL_CONN_IDLE_TIMER_RESTARTED_AFTER_READ,
 	_(QUIC_FL_CONN_RETRANS_NEEDED,
 	_(QUIC_FL_CONN_RETRANS_OLD_DATA,
@@ -491,7 +490,7 @@ static forceinline char *qc_show_flags(char *buf, size_t len, const char *delim,
 	_(QUIC_FL_CONN_EXP_TIMER,
 	_(QUIC_FL_CONN_CLOSING,
 	_(QUIC_FL_CONN_DRAINING,
-	_(QUIC_FL_CONN_IMMEDIATE_CLOSE)))))))))))))))))))))))));
+	_(QUIC_FL_CONN_IMMEDIATE_CLOSE))))))))))))))))))))))));
 	/* epilogue */
 	_(~0U);
 	return buf;
diff --git a/src/mux_quic.c b/src/mux_quic.c
index dc80c88fd..a7299fbc7 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -80,7 +80,10 @@ static void qcs_free(struct qcs *qcs)
 		qcc->app_ops->detach(qcs);
 
 	/* Release qc_stream_desc buffer from quic-conn layer. */
-	qc_stream_desc_release(qcs->stream, qcs->tx.fc.off_real);
+	if (qcs->stream) {
+		qc_stream_desc_sub_send(qcs->stream, NULL);
+		qc_stream_desc_release(qcs->stream, qcs->tx.fc.off_real);
+	}
 
 	/* Free Rx buffer. */
 	qcs_free_ncbuf(qcs, &qcs->rx.ncbuf);
@@ -561,7 +564,8 @@ static void qmux_ctrl_send(struct qc_stream_desc *stream, uint64_t data, uint64_
 	/* check if the STREAM frame has already been notified. It can happen
 	 * for retransmission.
 	 */
-	if (offset + data < qcs->tx.fc.off_real) {
+	if (offset + data < qcs->tx.fc.off_real ||
+	    (!data && (!(qcs->flags & QC_SF_FIN_STREAM) || qc_stream_buf_get(qcs->stream) || qcs_prep_bytes(qcs)))) {
 		TRACE_DEVEL("offset already notified", QMUX_EV_QCS_SEND, qcc->conn, qcs);
 		goto out;
 	}
diff --git a/src/quic_stream.c b/src/quic_stream.c
index f6adc2e43..80d56ba38 100644
--- a/src/quic_stream.c
+++ b/src/quic_stream.c
@@ -97,8 +97,7 @@ struct qc_stream_desc *qc_stream_desc_new(uint64_t id, enum qcs_type type, void
 }
 
 /* Mark the stream descriptor <stream> as released. It will be freed as soon as
- * all its buffered data are acknowledged. Does nothing if <stream> is already
- * NULL.
+ * all its buffered data are acknowledged.
  *
  * <final_size> corresponds to the last offset sent for this stream. If there
  * is unsent data present, they will be remove first to guarantee that buffer
@@ -107,9 +106,6 @@ struct qc_stream_desc *qc_stream_desc_new(uint64_t id, enum qcs_type type, void
 void qc_stream_desc_release(struct qc_stream_desc *stream,
                             uint64_t final_size)
 {
-	if (!stream)
-		return;
-
 	/* A stream can be released only one time. */
 	BUG_ON(stream->flags & QC_SD_FL_RELEASE);
 
diff --git a/src/quic_tx.c b/src/quic_tx.c
index 1420e103b..e5af014ed 100644
--- a/src/quic_tx.c
+++ b/src/quic_tx.c
@@ -491,10 +491,8 @@ int qc_send_mux(struct quic_conn *qc, struct list *frms)
 	}
 
 	TRACE_STATE("preparing data (from MUX)", QUIC_EV_CONN_TXPKT, qc);
-	qc->flags |= QUIC_FL_CONN_TX_MUX_CONTEXT;
 	qel_register_send(&send_list, qc->ael, frms);
 	ret = qc_send(qc, 0, &send_list);
-	qc->flags &= ~QUIC_FL_CONN_TX_MUX_CONTEXT;
 
 	TRACE_LEAVE(QUIC_EV_CONN_TXPKT, qc);
 	return ret;
@@ -1663,12 +1661,9 @@ static int qc_build_frms(struct list *outlist, struct list *inlist,
 				LIST_DEL_INIT(&cf->list);
 				LIST_APPEND(outlist, &cf->list);
 
-				/* Do not notify MUX on retransmission. */
-				if (qc->flags & QUIC_FL_CONN_TX_MUX_CONTEXT) {
-					qc_stream_desc_send(cf->stream.stream,
-					                    cf->stream.offset.key,
-					                    cf->stream.len);
-				}
+				qc_stream_desc_send(cf->stream.stream,
+				                    cf->stream.offset.key,
+				                    cf->stream.len);
 			}
 			else {
 				struct quic_frame *new_cf;
@@ -1710,12 +1705,9 @@ static int qc_build_frms(struct list *outlist, struct list *inlist,
 				cf->stream.offset.key += dlen;
 				cf->stream.data = (unsigned char *)b_peek(&cf_buf, dlen);
 
-				/* Do not notify MUX on retransmission. */
-				if (qc->flags & QUIC_FL_CONN_TX_MUX_CONTEXT) {
-					qc_stream_desc_send(new_cf->stream.stream,
-					                    new_cf->stream.offset.key,
-					                    new_cf->stream.len);
-				}
+				qc_stream_desc_send(new_cf->stream.stream,
+				                    new_cf->stream.offset.key,
+				                    new_cf->stream.len);
 			}
 
 			/* TODO the MUX is notified about the frame sending via