Custom subtitle settings applied to a whole series or season

I posted a thread for the “didn’t automatically work” issue already, but here I can try again. Haven’t seen any replies (I’ll copy a link here Forced subtitle not showing for MKV (default and forced flags set) )

PMS 1.14.1.5488 running on Windows 10 (both set to automatically update)

Player is Xbox One X with MS store app (no special version or side loading or whatever). Recently started seeing “stuck buffering issue” like many others in the forum, but that’s a different issue…

Embedded in MKV. I checked that the flags are actually set with mkvtoolnix (default and forced). I’d never changed subtitles settings beforehand to anything before noticing they didn’t work on this file. Then tried looking on the player to see if I could pick it manually…yep, but only for that one episode. Next episode had to do the same again (didn’t…I’ll just play on my computer for now). Hence the feature request after seeing another user’s post outside of the feature request area was ignored (from Jan 18 I think).

I don’t see a subtitle type listed in MKVToolNix GUI. “Codec ID: S_TEXT/UTF8” help? I’ve seen external SRT files before, but haven’t used them much before.

Played the file in my local browser and it looks like “English Forced (SRT)” is what it currently is using, after that manual setting from the Xbox. Didn’t realize the subtitle settings would apply across players.

Playing the 2nd file I’d never changed any setting for says “SUBTITLES None” currently.