Does anyone know why Plex keeps spiking CPU usage to 100% when playing h.265 files?

I have an Apple TV and Apple TV 4k and I cannot stream any h.265 files to either of them. I understand the 4th gen Apple TV might not support this (maybe) but the new Apple TV 4k clearly states this is supported so Plex should not be transcoding anything and simply be serving the file to the device, yet I see CPU usage is at 100% which clearly indicates it is transcoding the files.

I have tried 1080p and 4k files encoded with h.265 and neither one works, both in mp4 (which Apple TV should support) and mkv (which Apple TV should not support). Anyone have any suggestions or solutions to this which does not include converting anything to x.264?

The Apple TV app has not been updated to support hevc. Hopefully soon.