iPhone keeps going to 50% brightness

My iPhone 7 Plus with iOS 14.3 randomly reduces brightness to 50%. It has NOTHING to do with auto brightness. I know it's at 50% because when this happens I attempt to adjust the slider and there is no change in brightness from 50% to 100%. I've tried toggling auto brightness to see if it will reset, I have tried restarting my phone, neither works. This happens very often while in very bright outdoor sun-lit areas and suddenly I can't see anything on the screen. Btw I haven’t changed any components and I had it factory reset 2 weeks ago. It’s actually happening right now while I’m writing this.