Hi, Melissa.
Yesterday, I did a factory reset with iTunes (I couldn't reset otherwise because of the darn screen time passcode not working or letting me change the screen time passcode). I restored from iCloud backup instead of as a new device and it did not resolve the issue. I also did happen to try to operate the phone without my phone case and it was still acting up. I don't have a screen protector.
I went to sleep last night, woke up today and the phone was in perfect working order. I had already made an appointment to go to the Apple store (Genius), so I went ahead and did that. They ran diagnostics on it and it showed normal other than some battery degradation (90% iPhone X that's 3 years old). He recommended that if it started acting up again, to do a factory reset, but instead of iCloud backup, to "setup as a new device" (which you alluded to above). I will do that if the problem persists. If that doesn't fix it, it's time for a new phone, as the 3 year warranty is up and cost to replace is $549.
He did not have an answer specifically as to whether it was software (14.5 iOS update) or hardware (screen touch interface) related. I suspect it was the iOS update, as that's precisely when the problems began. Thanks for your response.