Stay away from the Rtings settings - they were done almost a year ago and there have been several firmware updates released since then. IMO the dedicated calibration thread is a waste of time. Lots of gaming settings, but very little in terms of the type of watching/view you want to do.
Try the below settings. I have also posted most extensive meter based settings in my signature below, but the technicolor Expert picture mode for both SDR and HDR content is the best and most accurate out there.
NOTE: For HDR settings, use the same "technicolor Expert" picture mode and adjust the basic Color setting to 48 to reduce some over-saturation issues. Leave the rest of the settings at default.
Also, on your AppleTV 4K, turn of dynamic range matching, turn on frame rate matching, and leave the home screen video set to 4K HDR. Basically what I'm getting at is to stay away from Dolby Vision if you like watching movies. It's just not implemented very well on the LG - unfortunately. . . . .
Energy Saving: Off
SDR Picture Mode: "technicolor Expert"
OLED LIGHT: 60
Dynamic Contrast: Off
Super Resolution: Off
Color Gamut: Auto
Edge Enhancer: On
Color Filter: Off
Gamma: 2.2 ( If you have 100% lighting control in the room and can get it really dark, then try BT.1886 or 2.4 )
Noise Reduction : Off
MPEG Noise Reduction: Off
Black Level: Low
Real Cinema: On ( Default - greyed out )
Motion Eye Care: Off