unresponsive/frozen screen iPhone X

You can't run diagnostics yourself on your iPhone X, but there is a replacement program for iPhone X that covers the device within 3 years of first purchase if it experiences similar issues to what you're describing.

iPhone X Display Module Replacement Program for Touch Issues - Apple Support

If you've bought your iPhone X after August 24, 2018, you might not be eligible for a free replacement, but you should Contact Support for more help with a repair.

My iPhone X has the latest updates, the screen is unresponsive, I've taken to the local Mac store they ran diagnostics and found nothing wrong. This seems to be a processor/processing issue. I reboot the phone and it usually works but some times I have to reboot multiple times to get working. What can be done to fix this bug issue?