+1 for this. I just bought a lifetime Plex Pass for the DVR, and it’s a bummer to find my recordings have Closed Captions that Plex can’t display.
FWIW, I’m using Plex on an Apple TV 4K, and an HDHomeRun. Live TV captions display perfectly. My recordings definitely include the closed captions (they’re visible in VLC, and I can extract an SRT using CCextractor on my Windows machine). However, when I try to playback my DVR recordings they show with no subtitles available (both in the Apple TV Plex app and the Infuse app). I think in theory I could try installing the CCextractor Linux packages to my Synology and have Plex run it as a postscript, but I’m not confident in my ability to do that properly (or if it can be done).
What’s frustrating is that the Silicon Dust app handles captions perfectly regardless of playback client, live/recorded, etc. But they don’t have an app for Apple TV. On my NVIDIA Shield, the HDHomeRun app from Silicon Dust is clunky looking, but it WORKS.
I am regretting the Plex Pass upgrade and all I can do is wait for a proper Apple TV app from SD or use my Shield in the meantime. I’m hoping Plex addresses this in a future release but I am not optimistic.