There are still problems. The mobile app recently got loads better but still has some pretty major issues with subtitles, showing that subtitles either are barely tested, or the dev simply doesn’t have the resources required or finished the app in a better way. Right now you cannot watch two episodes of a show in a row over Chromecast with subtitles without the last subtitles of the previous show frozen in screen and the new subtitles being display above those. Gotta disconnect Chromecast, shutdown the app, restart everything. This is super annoying but still light-years better than the previous mobiel app that would basically require a reinstall after each episode.
There are many other issues too, scrubbing is much better again, but still problematic and tents to freeze, requiring restarting everything.
Jellyfin is awesome but I can’t really let my wife use it, as she doesn’t have the computer patience that I have.