I have the same issue recently, exactly like what some of the users have described. If I turn on the screen quickly, this will happen. If turn off the sceen and wait for a while then turn it on again, everything looks ok. The irritating part is that I need to wait to turn it on.
I have the same issue. I brought it to the nearest service center. Their intial findings is the display. But they gave me a very high part quotation. So I decided not to pursue w/ the repair. I tried examining the phone & I discovered that if AOD is enabled, and followed by screen unlock/iris/fingerprint, the screen flickering will not happen. Maybe you give it a try if this also works for you.
I have same issue for over 2 months now. I have tried all suggestions except master reset but the problem still persist. Very infuriating. What else can I do please?