In case this is happening to you -
My second generation iPad Pro 12.9 is developing bright spots on the screen. I started with 1 and ignored it, now there are 7. They are like a small blob of pixels that are lighter than those around them. They show up on light backgrounds, not dark backgrounds. The more I search the internet the more I see that this is a common defect with no fix except replacement.
If yours is still under AppleCare then you should have them replace it right away. I found one post where somebody had theirs replaced 5 times and gave up after that.
Mine was just out of warranty. Apple wants almost the full cost of a new one to replace this common and well documented defect.