Bottom half of my screen keeps flickering/Darkening

Similar to an answered post from a few years ago the lower ~1/3 of my phone screen is dim/flickers on occasion, often darkening over time which increases the severity of the flickering and other times disappearing entirely. I can tell nothing is wrong with the phone as the flickering goes away during the shutdown screen and usually stays away for a bit after a restart.

I have tried digging around for a way to turn off DC Dimming as mentioned in the other post about this issue (www.ifixit.com/Answers/View/610354/Botto...) but haven't found a way to either get into or enable OnePlus Labs or enable/disable DC Dimming itself on the 6T (android 11).

I have had the phone since ~2019 and this problem only started recently, like within the past month.

If anyone has any helpful suggestions or knows anything about toggling DC Dimming on 6T's that would be incredible.

Thanks!