I would recommend installing Kodi on your chromecast and using the jellyfin addon[1] into Kodi instead. The app is garbage and Kodi is awesome.
(Don't use the Jellyfin Connect addon, it's different and I wouldn't recommend it)
(Don't use the Jellyfin Connect addon, it's different and I wouldn't recommend it)
JC has less bells and whistles with library integration and metadata but I'm not missing anything, really.
I had frequent connectivity and syncing issues with the other one but for me Connect Just Works. YMMV of course :)