Please include the actual version of the Plex app on your Apple TV. It can be found in the Plex app’s settings.
There are multiple “latest Apple TV clients” available right now depending upon whether or not you’re using the TestFlight builds.
The latest TF builds aim to improve playback performance in a couple of ways, including a new rendering engine that better leverages the ATV4K’s hardware. I’m not saying there are no issues, but things are improving (generally).
Here’s a link to the beta thread. Note that there are a finite number of TestFlight slots, so you may not be able to immediately join.
