I ALREADY TRIED WIPING THE PHONE AND RESTORING FROM CLOUD BACKUP. iPhone XS. Touch screen goes erratic 1 to 10 minutes after unlocking, usually 1 minute. Does not respond to most touches and sometimes creates ghost touches when my hand is far from the screen. Locking and unlocking the phone fixes it for 1 minute 100% of the time. Issue started immediately after latest update, 13.5 or 13.5.1 I think. Never the slightest problem before.
Might be related to contact with a millimeter of water which is weird because these phones are supposed to be water resistant and it wasn't even submerged. Or something else made the problem go away on its own. Hopefully it doesn't return.