Maybe that happened to me last night and this morning. The screen wouldn’t respond to touch last evening.
I let the ipad shut down.
Tried this AM and again, would not respond to touchscreen.
Ipad waited for me to slide the arrow to the right but since no response, it just shut down.
Went online, instructed to press both those buttons.
It worked. Yea !
Should have mentioned, this is a Gen 2 ipad.
It’s possible that is a locked Java script problem as well. It’s also possible it is just a system lockup. Forcing a restart can solve both. The phishing expedition I describe above is more, because it won’t go away until you clear the script and the requestor which will keep popping up, so long as it is in the cache and Safari is running on a soft-start.