A shot in the dark, but try setting them up to connect to a hostname instead of an IP - maybe if the name doesn’t resolve then it won’t get stuck?

Handbrake has the option to autodetect black bars and crop them out. But you have to reencode the file, unfortunately.

Aurora ran fine for me in bottles after adding windows fonts to the environment. Sorry i don’t have anything more specific, but you can run aurora on linux fairly easily.