You can change audio tracks on the film’s library page by selecting the 3 dots and then ‘select audio track’.
re: the file in question.
The video is 4K HDR10 so will direct play fine.
The 1st audio track is TrueHD - this will result in a transcode to AAC.
The 2nd audio track is AC3 - although this would usually direct play, the Plex Samsung app forces a transcode to AAC as it doesn’t like anything that isn’t the 1st audio track. Even if the 2nd audio track is AAC, it’ll still switch to Direct Stream.
PGS subs are Direct Play supported as of some point in the past year.
So basically, without remuxing the file you’ll be transcoding the audio.
I tested the exact same file on my 2022 Samsung QN95B - though for now I’ve only tested a 2GB / 10min chunk that I cut using MKVtoolnix - and with the subtitles enabled the playback crashes and burns after around 3mins 30secs in the way you describe.
Disable the subs and it seems fine (though I’ve not let it play for more than 6-7mins).
Remux, make the AC3 the 1st audio track, and it also seems to play fine (Direct Play now). With or without subs. Though the full 40GB file might give you more problems due to the internal subs which cause heavy disk usage (Very high Disk usage when using internal subtitles on Samsung (can cause buffering/failed playback) - #2 by davef_d)
The only setting of yours that doesn’t match mine is I have the ‘normalize multi-channel audio’ setting disabled (no tick). I think that’s all done on the player side though so I don’t know how much of a difference it makes.
