Playback 4k HDR & HFR

I am having this issue when playing for example gemini man 4k hdr and 60 HFR. I am using latest coreelec nightly on X96 Max 4/32.

You need to enable GUI scaling in CoreELEC settings and reboot.
GUI will be rendered at 1080P, but 4K video will still play correctly, and the artifacts will be gone.