There are too many complaints about the iPad touchscreen for it to be anything but a device issue. Very frustrating.

Nothing to be done.

This is NOT something you are going to want to read, but these are the facts/issues, as I know them, for the past almost 4 years.

The intermittent, unresponsive touchscreen issues with higher priced, larger screen iPad Pro and iPad Air models are a well known and well documented, here, in the iPad support communities.

Any iPad model with a 10.5 inch screen seem particularly susceptible to this Intermittent,unresponsive touch screen issue.

This still affects a small, but continually growing minority of random 2017 through present iPad Pro and iPad Air models and its user base.

Now, after nearly 4 years of this nonsense, there is still no confirmed cause and fix/solution from Apple.

NONE!

Getting one of these defective units is very random and is ONLY one of a small handful of issues going on with higher priced, larger screen iPad models that has prevented me from purchasing a new iPad Pro or new iPad Air for the past 2-3 years.

Apple and Apple support have no real fixes or solutions to this issue and, most likely, at this very late date, never will.

Again, Sorry.

You can continue to try simple hard resets of your iPad year and model, but this quick fix is, usually only a temporary solution.

For iPad models with a Home button, do a simple hard reset of your iPad by holding down both the Home and sleep/wake/power button simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons.

OR

For much newer design iPad models, without a Home button, try the new simple hard reset procedure for the new 2018/2020/2021 iPad Pros, 2020 iPad Air 4 and 2021 iPad Mini 6 models.

1. Press and release the volume up button.

2. Then immediately press and release the volume down button.

3. Then, press and hold the single sleep/wake/power button You will see the Slide to Power off button, but keep on holding down the power button until you see the Apple logo, then let it go.

Once you have performed all the steps, wait for a few seconds and your 2018 iPad Pro will boot up completely to the iPad Pro’s Lock screen.

If you have a screen protector on this iPad Pro, remove it as the screen protector makes the touch screen and Pencil experiences worse.

Also, try removing your iPad's case ( it maybe too tight a fit ) and try using your iPad without it to see if this helps, or not, with your iPad touchscreen issue/s

There is absolutely no solution/s to these later iPad Pro/iPad Air touch screen issues.

Apple support can only offer superficial, “band-aid” bandage-like advice/fixes/solutions.

You can contact Apple support, but your iPad Pro/later iPad Air model maybe too old for Apple to offer any type of free or in-warranty iPad replacement and Apple will ONLY offer “band-aid“-like advice/fixes/solutions to this issue.

Apple support is pretty much clueless to this issue and Apple, itself, has never, publicly, acknowledged this issue or issued any type of device recalls.

This is something you probably didn't want to learn, but doesn't change any of the currently known facts.

So Sorry & Best of Luck to You!