This happens with subtitle tracks as well, on mobile and Chromecast with Google TV, subtitle burn-in for picture formats only, I have a movie (MKV, HEVC) with English PGS subtitles, English and Spanish VOBSUB, these appear at the top and all play correctly, then there are 16 SRT tracks, all embedded (but I can confirm the SRT index is broken with external and internal subtitle tracks too), when PGS or VOBSUB subtitles are present, selecting an SRT track incorrectly uses the wrong subtitle index, so selecting Arabic SRT (first SRT subtitle, 4 overall) uses English PGS, selecting Croatian SRT (#2 SRT, #5 overall) plays English VOBSUB, Danish SRT (3, 6) uses Spanish VOBSUB, Persian SRT (4, 7) finally uses an SRT track, but it’s Arabic, the issue affects all other SRT tracks, the last 3 embedded SRT tracks are inaccessible without buffer internal/external tracks.
My media server runs on unRaid if that matters, I don’t believe the issue affects browser viewing but I can’t remember (I mostly use my TV), also switching from SRT subtitles to PGS or VOBSUB often causes the app to restart.
Update: I can confirm that the issue is to do with subtitle burn-in being disabled, if enabled, all subtitles play correctly.
