On one of my PCs running Windows 10, I have a WinTV quadHD tuner card. I setup Plex Media Server on it yesterday and recorded some content.
When I play that content from Plex for Windows or Plex HTPC, I can’t get any subtitles to show, even if I manually select the subtitles track. These same clients play subtitles fine from other contents - MKV movie files for example.
What’s odd is that Plex for Android on my smartphone shows this OTA TV content just fine with subtitles. Plex on Chromecast also shows the subtitles with that content. Plex in a web browser on a PC also shows subtitles.
I haven’t tried Kodi or Plex yet on my Raspberry Pi, Odroid N2, Google TV, FireStick 4K, etc. I think I have about 60 Plex clients signed in to my Plex pass All inside my home, too.