diff --git a/api-extractor/report/hls.js.api.md b/api-extractor/report/hls.js.api.md
index 2cc281ae8b5..2ef051373b8 100644
--- a/api-extractor/report/hls.js.api.md
+++ b/api-extractor/report/hls.js.api.md
@@ -81,6 +81,8 @@ export interface AudioTrackSwitchedData {
 //
 // @public (undocumented)
 export interface AudioTrackSwitchingData {
+    // (undocumented)
+    groupId: string;
     // (undocumented)
     id: number;
     // (undocumented)
@@ -2007,6 +2009,8 @@ export interface SubtitleTracksUpdatedData {
 //
 // @public (undocumented)
 export interface SubtitleTrackSwitchData {
+    // (undocumented)
+    groupId?: string;
     // (undocumented)
     id: number;
     // (undocumented)
diff --git a/src/controller/audio-stream-controller.ts b/src/controller/audio-stream-controller.ts
index 1170f508ebd..2668a54aba6 100644
--- a/src/controller/audio-stream-controller.ts
+++ b/src/controller/audio-stream-controller.ts
@@ -7,7 +7,6 @@ import { FragmentState } from './fragment-tracker';
 import { Level } from '../types/level';
 import { PlaylistLevelType } from '../types/loader';
 import { Fragment, ElementaryStreamTypes, Part } from '../loader/fragment';
-import FragmentLoader from '../loader/fragment-loader';
 import ChunkCache from '../demux/chunk-cache';
 import TransmuxerInterface from '../demux/transmuxer-interface';
 import type { TransmuxerResult } from '../types/transmuxer';
@@ -364,6 +363,7 @@ class AudioStreamController
     event: Events.AUDIO_TRACKS_UPDATED,
     { audioTracks }: AudioTracksUpdatedData
   ) {
+    this.resetTransmuxer();
     this.levels = audioTracks.map((mediaPlaylist) => new Level(mediaPlaylist));
   }
 
@@ -374,7 +374,7 @@ class AudioStreamController
     // if any URL found on new audio track, it is an alternate audio track
     const altAudio = !!data.url;
     this.trackId = data.id;
-    const { fragCurrent, transmuxer } = this;
+    const { fragCurrent } = this;
 
     if (fragCurrent?.loader) {
       fragCurrent.loader.abort();
@@ -383,10 +383,7 @@ class AudioStreamController
     this.clearWaitingFragment();
     // destroy useless transmuxer when switching audio to main
     if (!altAudio) {
-      if (transmuxer) {
-        transmuxer.destroy();
-        this.transmuxer = null;
-      }
+      this.resetTransmuxer();
     } else {
       // switching to audio track, start timer if not already started
       this.setInterval(TICK_INTERVAL);
diff --git a/src/controller/audio-track-controller.ts b/src/controller/audio-track-controller.ts
index 3396b99afad..c06f0d60827 100644
--- a/src/controller/audio-track-controller.ts
+++ b/src/controller/audio-track-controller.ts
@@ -188,11 +188,17 @@ class AudioTrackController extends BasePlaylistController {
 
     const lastTrack = tracks[this.trackId];
     this.log(`Now switching to audio-track index ${newId}`);
-    const { id, name, type, url } = track;
+    const { id, groupId = '', name, type, url } = track;
     this.trackId = newId;
     this.trackName = name;
     this.selectDefaultTrack = false;
-    this.hls.trigger(Events.AUDIO_TRACK_SWITCHING, { id, name, type, url });
+    this.hls.trigger(Events.AUDIO_TRACK_SWITCHING, {
+      id,
+      groupId,
+      name,
+      type,
+      url,
+    });
     const hlsUrlParameters = this.switchParams(track.url, lastTrack?.details);
     this.loadPlaylist(hlsUrlParameters);
   }
diff --git a/src/controller/base-stream-controller.ts b/src/controller/base-stream-controller.ts
index fea77cd1acd..faaf3710dea 100644
--- a/src/controller/base-stream-controller.ts
+++ b/src/controller/base-stream-controller.ts
@@ -121,10 +121,7 @@ export default class BaseStreamController
     if (frag) {
       this.fragmentTracker.removeFragment(frag);
     }
-    if (this.transmuxer) {
-      this.transmuxer.destroy();
-      this.transmuxer = null;
-    }
+    this.resetTransmuxer();
     this.fragCurrent = null;
     this.fragPrevious = null;
     this.clearInterval();
@@ -1228,10 +1225,7 @@ export default class BaseStreamController
             this.warn(
               `Could not parse fragment ${frag.sn} ${type} duration reliably (${parsedDuration}) resetting transmuxer to fallback to playlist timing`
             );
-            if (this.transmuxer) {
-              this.transmuxer.destroy();
-              this.transmuxer = null;
-            }
+            this.resetTransmuxer();
             return result || false;
           }
           const drift = partial
@@ -1269,6 +1263,13 @@ export default class BaseStreamController
     }
   }
 
+  protected resetTransmuxer() {
+    if (this.transmuxer) {
+      this.transmuxer.destroy();
+      this.transmuxer = null;
+    }
+  }
+
   set state(nextState) {
     const previousState = this._state;
     if (previousState !== nextState) {
diff --git a/src/controller/stream-controller.ts b/src/controller/stream-controller.ts
index 97e5257cbba..5dba9b6e396 100644
--- a/src/controller/stream-controller.ts
+++ b/src/controller/stream-controller.ts
@@ -715,13 +715,6 @@ export default class StreamController
     );
   }
 
-  private resetTransmuxer() {
-    if (this.transmuxer) {
-      this.transmuxer.destroy();
-      this.transmuxer = null;
-    }
-  }
-
   private onAudioTrackSwitching(
     event: Events.AUDIO_TRACK_SWITCHING,
     data: AudioTrackSwitchingData
diff --git a/src/controller/subtitle-stream-controller.ts b/src/controller/subtitle-stream-controller.ts
index 9072ad69cdb..19549e81cff 100644
--- a/src/controller/subtitle-stream-controller.ts
+++ b/src/controller/subtitle-stream-controller.ts
@@ -5,7 +5,6 @@ import { findFragmentByPDT, findFragmentByPTS } from './fragment-finders';
 import type { FragmentTracker } from './fragment-tracker';
 import { FragmentState } from './fragment-tracker';
 import BaseStreamController, { State } from './base-stream-controller';
-import FragmentLoader from '../loader/fragment-loader';
 import { PlaylistLevelType } from '../types/loader';
 import { Level } from '../types/level';
 import type { NetworkComponentAPI } from '../types/component-api';
diff --git a/src/controller/subtitle-track-controller.ts b/src/controller/subtitle-track-controller.ts
index 13250f3210c..473f2520c06 100644
--- a/src/controller/subtitle-track-controller.ts
+++ b/src/controller/subtitle-track-controller.ts
@@ -354,8 +354,14 @@ class SubtitleTrackController extends BasePlaylistController {
     this.log(`Switching to subtitle track ${newId}`);
     this.trackId = newId;
     if (track) {
-      const { id, name, type, url } = track;
-      this.hls.trigger(Events.SUBTITLE_TRACK_SWITCH, { id, name, type, url });
+      const { id, groupId = '', name, type, url } = track;
+      this.hls.trigger(Events.SUBTITLE_TRACK_SWITCH, {
+        id,
+        groupId,
+        name,
+        type,
+        url,
+      });
       const hlsUrlParameters = this.switchParams(track.url, lastTrack?.details);
       this.loadPlaylist(hlsUrlParameters);
     } else {
diff --git a/src/types/events.ts b/src/types/events.ts
index 02cb7a12428..fc21d76b892 100644
--- a/src/types/events.ts
+++ b/src/types/events.ts
@@ -155,6 +155,7 @@ export interface LevelPTSUpdatedData {
 export interface AudioTrackSwitchingData {
   id: number;
   name: string;
+  groupId: string;
   type: MediaPlaylistType | 'main';
   url: string;
 }
@@ -176,6 +177,7 @@ export interface SubtitleTracksUpdatedData {
 export interface SubtitleTrackSwitchData {
   id: number;
   name?: string;
+  groupId?: string;
   type?: MediaPlaylistType | 'main';
   url?: string;
 }
diff --git a/tests/unit/controller/subtitle-track-controller.js b/tests/unit/controller/subtitle-track-controller.js
index 4a098831ca3..67d794cbf70 100644
--- a/tests/unit/controller/subtitle-track-controller.js
+++ b/tests/unit/controller/subtitle-track-controller.js
@@ -129,6 +129,7 @@ describe('SubtitleTrackController', function () {
         'hlsSubtitleTrackSwitch',
         {
           id: 1,
+          groupId: 'default-text-group',
           name: 'English',
           type: 'SUBTITLES',
           url: 'bar',
@@ -164,6 +165,7 @@ describe('SubtitleTrackController', function () {
         'hlsSubtitleTrackSwitch',
         {
           id: 0,
+          groupId: 'default-text-group',
           name: 'English',
           type: 'SUBTITLES',
           url: 'baz',