subtitles in ripped blu-ray video (pgs format) crashes Plex playback



Hi, I am using the Plex server on my Nvidia Shield TV and it works OK. Not really well, compared to Kodi direct play I used before, but normally it runs.
But, I archived a lot of my movies and TV shows from my Blu-rays, in 1080p and including the subtitles.
If I play a video without subtitle, everything is OK - even it takes a while before the film or show starts.
As soon, I chose a subtitle included in the .mkv file (in pgs graphic format), the playback stops or crash. It shows "server isn´t able to transcode"... But why transcoding? Shield itself and also my LG smart TV is able to handle the .mkv with the pgs subtitles!

Interesting thing: If I do have text subtitles in i.e. srt format separat from the video file and chose this - everything is fine.

In my honest opinion, it can only be a configuration issue - as no transcoding seems necessary. Can anybody help to find the correct setting?!

many thanks for your help.



Support for PGS subtitles varies by client.

I've a Shield TV and Amazon Fire TV Gen 2.

Plex client on Shield TV direct plays PGS subtitles.

Plex client on Amazon Fire TV Gen 2 transcodes video when PGS subtitles are selected.


So, anyhow it is a client duty whether or not being able to display directly or request transcoding?