Android TV 0.17 (to many errors. giving up)

[TheDreadPirate]

ffmpeg never supported mp2 in mp4 container and if you really want those files to be played you need to ask the client to provide an option to remove mp3 support from mp4 container as a whole

I think my english is just not good enough to understand that answer.
ffmpeg never supported mp2 audio in a mp4 file? But like every video-converting-program ever lets me choose "mpeg layer 2 audio". Handbrake, vlc, ...

Jellyfin server can't tell the different between MP2 and MP3 audio (ffprobe limitation) when they are in a MP4 container and puts "MP3" as the audio codec when it actuality it is MP2.  The client is told the audio is MP3, the client thinks it is compatible and doesn't ask for a transcode, but it ends up receiving MP2 audio that it can't play.