Jellyfin Failure

[PPRJack]

I really wanted to like Jellyfin but way too often when I try to use it, I have problems.
Now I am NOT a newby, I CAN work through an issue here and there BUT, 
Subtitles are NOT working (for some content, not sure why) 
and NOW 5.1 surround sound is NOT working ( for some content, not sure why) 
I have Open Subtitles installed, plugged in my Open Subtitles username and password and verified they are working, re-scanned my Libraries with the 'Allow All' subtitles flag set. 
NO menu for searching subtitles, no indication that Jellyfin can even do subtitles except for the occasional content that just seems to work?! 
Whenever I experience these issues I just feed that content to my Plex Proxmox container, and it 'Just Works'!
I am about to nuke my Jellyfin server, also a Proxmox container, and rebuild it in hopes that I just have a corrupted install.
If THAT doesn't work I am Giving Up on Jellyfin. too many issues!
My hobby is watching TV and Movies, NOT troubleshooting Jellyfin. 
Any suggestions for a good authoritative guide for setting up Jellyfin are welcome. 
The Proxmox container build is NOT the issue, the post install config is where I might be having problems.
I must be doing something wrong.

[jravin]

A lot to chew on.

Up front, for an authoritative setup guide: Installation | Jellyfin

Double-check permissions.

Make sure the Proxomox container has access to all audio/video codecs.

Enable transcoding logs to debug the subtitle/audio issues.  Feel free to share here...

Some other possibilities:

Maybe certain files or embedded subtitle formats are not compatible with jellyfin?  Doubtful as you are using jellyfin to get the subtitles.

Double-check any plugin settings.  Make sure they are pointing where they should be pointing.  Are the subtitle files in the same directory as the media files?

In the Transcoding settings, try testing the 'Allow subtitle extraction on the fly' option.

ffmpeg logs?

jellyfin logs?

IMHO, jellyfin provides more configuration flexibility than plex, which sometimes causes users migrating from plex into jellyfin to pause.  You got this.  Jellyfin is amazing.