Lordy, I know what you're going through. I had the very same iPad and sold it last year because that was driving me nuts.
I had the same one, thought I’d have to pay for a replacement at the Apple Store, but they verified the issue and swapped it out for me. The replacement worked much better.
I often get touch and brightness issues with my 2nd gen 12.9. Doing a basic settings reset tends to fix it for a few weeks but it’s annoying. (i also have light bleed on the right side)
I took mine in assuming I’d have to pay for the repair (mine had the light bleed, too). They ran a color test on it in the store and swapped it out. Don’t wait for a recall, take it and at least see what they say.I‘m hoping Apple will acknowledge the issues with the 2nd gen iPP12.9 and repair it.