Subtitle support is just all over the place on Roku, unfortunately. I’ve being trying for months to solve one little problem with no help from anyone.
(Non-forced Subtitles NOT default anymore) or (Plex is selecting forced subtitles over regular subtitles)
There’s also a very serious issue with external subtitles getting completely desynched after resuming, but that’s being ignored too.
(Roku - External subtitles out of sync when resuming playback)
I use subtitles for everything i play since I enjoy the original audio but I’m not a native english speaker, and the support on these issues has been non-existent.