Plex picking up wrong subtitles for an individual episode

Hi,

I’m having a problem with one specific episode of Star Trek Deep Space Nine. (S05E09). Plex is incorrectly using the subtitles for S05E02 instead.

Both subtitles files (.en.srt files) exist correctly on my server, but I don’t think I’m using Local Media Assets. (Not ticked under Shows/TheTVDB although it is ticked under Shows/The Movie Database.).

Under Agents/Shows/TheTVDB I have
TheTVDB
Opensubtitles.org
Plex Theme Music
Everything else is unticked.

Under Agents/Shows/The Movie Database I have:
The Movie Database
Plex Theme Music
Local Media Assets (TV)
Everything else is unticked.

I’ve checked the subtitles on Open Subtitles and they are correct. (3 versions available, here: https://www.opensubtitles.org/en/subtitles/4291847/star-trek-deep-space-nine-the-ascent-en ).

Is it getting the wrong ones from TheTVDB? I can’t see Subtitles there to check…

Alternatively, is there some sort of bug?

Note: correct subs start “don’t you think you might be overpacking”, NOT “Captain’s Log”…

Thanks for your help.

James

PS, all my Plex players (web, android, Amazon Fire Stick) indicate that external SRT files are being used.

In fact this happens for S05E09 - S05E13 inclusive. They all incorrectly use the subtitles from S05E02. For episodes after that, the problem “fixes itself”…

James