Making the computer sleep will remove this symptom for a while.
Tried disabling hardware acceleration (GPU) via setting or gSwitch, resetting SMC and PRAM/NVRAM, and rebooting. Apple diagnostics has not been identifying any issues.
MacBook Pro – Fix Bottom Part of Screen Mirroring Top
screen
Best Answer
Wow - unless you’re sure it’s software, I would get it to Apple Service for a look. One method to perform a quick check is boot to recovery - hold option and R. If the firmware screen is broken, you know it’s GPU / CPU.
If the firmware screen is perfect, you would want to back up and then perform an erase install. It’s possible hardware failure could happen only when all graphic drivers are fully loaded and optimized / accelerated.