The VideoLAN Forums

Timings for Bluray discs and MPEG-TS in general differs from typical file formats, so yeah, regular subtitles can't work.

What can I do to subtitle BDMV correctly?

If you choose to add your own subtitles obtained from elsewhere instead of using the subtitles that come with the BDMV directly when playing the BDMV, the player will not be able to continue to play normally and you will have to quit and then play again. How can I add other subtitles while playing B...