Subtitles on roku no longer working

[xterminal]

Possibly a different issue, but I am also having problems with subtitles on the Roku client (not embedded, though--the video file is mkv, but I'm using external .srt subs. The system sees them and says it's running them on the Roku client. When I play the file through Jellyfin on the server using the web client, I see the subs).