It's been a year or two since I gave up on Jellyfin, so maybe it's better now... But the Android TV client was rough, rough, rough when I tried using it.
If you watched Live TV, the transcode buffer would just keep going and fill your entire disk over the course of a few days after you shut down the client and stopped watching.
It was a coin toss whether you'd actually be able to stream any given movie. If you had media with more than 6 audio channels, and also needed to transcode (because you live in the U.S. and don't have unlimited upload bandwidth).... playback would just die right around the 5-10Mbps range. I spent a weekend on the forums chasing down the exact scenarios that caused this one, someone had a Pull Request that fixed it in a matter of hours (by mimicking the transcode logicr of the official desktop client)... and the dev told them to kick rocks