Audio stream does not change on Firefox and Chrome

[gdnmhr]

Describe The Bug

I have an mp4-file with two audio streams, muxed together using MP4Box. When I try to change the audio track, nothing changes, the default one is still played. This issue occurs on Firefox and Chrome/MS Edge, but not on Safari.

Enabling the Chromium flag enable-experimental-web-platform-features somehow fixes the issue (seems like this feature is quite buggy in Chrome).
I digged a bit deeper into the issue and found out, that player.canSetAudioStreamIndex() returns false without the flag enabled, thus the player requests a new stream for this audio track. Observing the playback info, I noticed that for both audio streams, the file is directly playing.
As direct play is theoretically supported on this device, the server responds with the original stream and nothing changes. Therefore, the server needs to be forced to remux the file if a custom audio stream is requested which does not happen currently.

Steps To Reproduce

1. Have a file with two audio streams
2. Switch between the streams
3. Observe the audio output

Expected Behavior

The audio should switch to the requested stream.

Logs

Screenshots

System (please complete the following information):

• Platform: Server: Linux, Client: Windows
• Browser: Firefox, MS Edge
• Jellyfin Version: 10.8.5

Additional Context