Let me clarify...I can force the show into Dolby or HDR and it looks fine, but when I set my Apple TV to 4K SDR @ 60 hz(which is where it should be set, I am told) that is where the problems seem to lie.Sorry to read about your pic problems. I'm using an Apple 4K box also on a LG Oled and have had no problems. Looks great in Dolby Vision 4K. Not trying to rub it in. Perhaps post in the LG TV thread of the display forums. Did you download the latest update from Apple?
Maybe I'll try to take a video of the problem this weekend.