iPad Pro 11" - Touch Screen Unresponsive

I am convinced this is a software problem, not a physical problem with certain touchscreens. Here’s my rationale:

(1) I own two iPad Pro’s, a 2nd gen 10.5 and 3rd gen 12.9. I have owned the 10.5 for about 18 months and the 12.9 for about 3. Both have started to show screen sensitivity issues increasing over the past couple of months, as iOS updates have been automatically installed. Both are running 12.1.4

(2) The 10.5 has become very sensitive to movement. If I try to type while moving (I use it on an Eliptical Trainer nearly every morning) it does not detect about 50% of my keystrokes if I hold the iPad. If I put it down on the book stand on the trainer and type with one finger, the problem is much less apparent. This was not happening a few weeks back. I’m not sure which iOS update caused the issue.

(3) The 12.9 has the “unresponsive” issue that many on this forum point out. I have noticed it is mostly later in the day, after I have used the iPad on and off through the day. It seems correlated with screen cleanliness. If I keep the screen completely free of prints and smudges, it works much more reliably.

(4) Unresponsiveness also seems correlated with movement on the 12.9. If I suddenly pick up the iPad and immediately try to swipe/scroll on a webpage or email list, or other app (and if the iPad is kind of smudged) it is unresponsive for several seconds. Same thing happens when suddenly rotating or putting the iPad down on a table, again, if I have smudges/prints.

I recall reading somewhere that the screen on the 3rd gen iPads was changed to give the pen a more realistic feel. I wonder if the new screen and tweaking of touch algorithms on Apple’s part are causing the problems. I also suspect some iPads are more sensitive than others.

I had an appointment scheduled at my local apple store to convince them I needed them to replace my 12.9 iPad but cancelled when I couldn’t re-create the unresponsiveness when keeping the screen completely clean.