iPad Pro 12.9 Screen Light Bleed
My screen also has this issue, which I've seen posted a few other places. When I took it to an Apple store, they had a technician look at it and told me the screen was fine, maybe a few bad pixels, and offered me a credit if I traded it in for a new one. It's a little over (2) years old. I've brought in the original one I bought because the touchscreen stopped responding. They replaced it on the spot. I don't understand why they're giving me the run around this time.