Sub titles stop after a minute until I rewind 10 seconds then they start again, repeat, repeat

Can’t seem to read any old answers on this topic on my i_ad so asking again, why do subs just stop usually after 60 seconds, then i just hit a short back up and they start again. over and over

def bad graphics for this page with chrome on ipad - sorry for needing to reply as my first screen went blank. i am streaming locally via ethernet direct from Windows 11 server, media is direct attached 33TB drive solely for plex. All movies english or otherwise will start subs with “forced setting” but they vanish in 60 seconds then i discovered i can back up 10 seconds and they will start up again for another 60 seconds or so. 4k, 1080p or less nothing changes the vanishing subs. everything is up to date as per usual.

May I ask if you’re using the latest beta PMS which did a major change to FFMPEG? Do you recall when this started happening? Are you playing on a Roku? Are your subs SRT format?