The Plex server is basically OK, the trouble you have is with the Plex clients.

I bought an Xbox One instead of a PS4 even though I like the anime games on the PS4 because the Xbox One has a perfect Plex client and the PS4 client is known to be "janky"

I struggled with cheap Android TV devices and broke down and bought a NVIDIA Shield TV because it has a perfect Plex client too with adequate hardware.