Issue present on both Roku apps
Plex 6.3 build 4
Plex Preview 6.3 build 5
At present unable to get any subtitle visible in any video regardless of direct play or transcoding video or audio.
Also unable to change audio language at any time during playback during direct play or during transcoded stream. Defining different audio prior to loading video does not work. Only workaround is to reduce playback quality during stream to change audio however changing quality back to original or higher then reverts audio back to previous audio stream.
Issues appear to be present in all my media for movies, mp4 as well as external subtitle files.
Reset server settings and reinstalled both apps with issue persisting.