I can't say I've ever seen any showstoppers for the jellyfin Roku client, but I will say it seems rather inconsistent when using the media options menu after selecting a movie. Sometimes choosing a different video reverts to the default top choice when you hit play. Sometimes the audio selections don't match up with the chosen video but rather a different video option, meaning any choice is the wrong choice. At one point I even got the client to say that AAC Stereo was both the chosen Video and Audio. It's really hard to describe and never enough a nuisance to wade through the process of opening an issue.