Before you roll back to a working version, so that the Plex team can help with this can you do the following to provide logs where the issue is reproduced so they can see if there is anything in the logs that might give a clue?
(Stolen from an @ChuckPa post):
Please verify DEBUG logging is on, VERBOSE is off
Play again for 20 seconds
Stop
Wait 20 seconds
Download the logs ZIP file (under Server - Troubleshooting)
Screenshot of making sure DEBUG logging is on and not VERBOSE (stolen from an @FordGuy61’s post):
Settings → Server_Name → General
Also, can you try what @tom80H asked in his last post post about checking the file in something like VLC and see if the subtitles work properly? Also, can you post the XML like he mentioned as well for that.
With the XML from the OP I am seeing that the subtitles are actually the closed captioning (eia_608), so it’s possible something got messed up where Plex isn’t properly processing those.
-Shark2k
