The lockups are common with any iPad. I did have a unique one yesterday with my new 12.9 though. I had it with me at work, and the screen went to sleep while I was talking with my boss. When I came back I couldn't get the screen to wake up, just nothing but black. I did feel like I could see a very very faint image of my app window, but not enough to really see anything. After hitting the home button maybe 10-20 times finally the screen work up and I could touch my finger tip to get back in. Anyone ever experience anything like this? (No not on iOS 11)
I experienced this starting back when I first got my 9.7" ipad pro in Nov 2016. It was on the current ios at the time. I had replaced an ipad air 2 with this 9.7" ipp and had no issues with the air 2. Anyway, I solved this constant freeze on my 9.7 ipp with installing 1Blocker. Zero freezes since installing.
¯\_(ツ)_/¯ - this has happened to me as well. I guess the increased complexity of iOS means that bugs are more prevalent, but it is an unpleasant UX in general. Hopefully future versions of iOS won't require hard reboots so often during normal usage.