Chosen Solution

After replacing the screen on a Pixel 3a, the screen will flash (like a single bright strobe) when waking the phone up or sometimes when opening an app. Also, some screen taps are missed and entering text has to be done slowly to prevent missed letters.

It sounds like a bad connection. Disconnect the battery and unhook the screen and make sure that there are no bent pins. I would then clean the connectors with a qtip and alcohol and a soft brush. Put it back together and hook up the battery last

Hello, Brandon! Did you manage to find a solution?