Subtitles .srts not loading

Curious, anyone have any luck with their srt files working. Mine haven’t worked for along time and I can’t figure out why. Media server up to date, Plex app on Apple TV and iPhone up to date, srt labeled properly. Example S01e01.mkv S01e01_English.srt. Any thoughts

Should be:

S01e01.en.srt

or

S01e01.eng.srt

Ref:
https://support.plex.tv/articles/200471133-adding-local-subtitles-to-your-media/

But only if the video file is named
S01e01.mkv

If it’s named
Seriesname - S01E01.mkv instead,
then the accompanying subtitle file must be named as well
Seriesname - S01E01.eng.srt

i.e. it must use an identical name to the video file, apart from the extension (and language code).

So I redid some of the srts that i had labeled wrong and it started working on some files. Then all sudden no subtitles again and all i could think of that changed was i updated the server. Still nothing working except the odd file. Is this common?>