I have been using Jellyfin on Android and Windows viewing DVD movies that were converted with Handbrake into M4V files in H.265 format. The foreign subtitles and closed captions have always been embedded and passed through by handbrake, and I’ve never had any issues playing the subtitles over th years with VLC/KODI/Plex etc. Even On Windows or android Jellyfin clients I’ve had no issues. My parents only use Roku however, and the only way I’ve been able to get the subtitles working for them is by creating a separate .srt file in the folder that has the video. I’ve tried .ass files using subtitle edit program without success. Do I need to reencode all my movies with subtitles and extract them as srt files for them to work on Roku? Or is there a better way to to get them working on Jellyfin Roku? Also, is there a format other than srt that is compatible with Jellyfin Roku?