You may be correct, i noticed that when I click the LG menu for the tv. It opens the hdmi options etc and in the background the image goes back to bright white. I guess i probably do have that on. I have a 2017 and I thought this was a 2018+ feature for LG oleds. maybe i have it turned on somewhere in the settings.I never noticed that, sounds like it's probably the logo luminance setting though. When it detects a static, bright image, it will dim. If your turn that off, you increase your risk of burn in, but I think it'll be brighter.
Thanks for the suggestion. in any case, it doesnt interfere with gameplay, or scenes, it is just that one menu screen. The other games don't do that.