https://wccftech.com/ios-15-causing-intermittent-touch-issues-on-iphone-13-and-older-models/

Apple released iOS 15 to the general public a little over a week ago with a boatload of new forward-facing features. While the new update is packed with new additions, some iPhone 13 users are reporting intermittent touch issues on their devices. If you are unfamiliar, the screen does not register touch inputs by the user. Scroll down to read more details on the issue and how you can temporarily work around it.

It was reported on Reddit, Twitter, and Apple Support that iPhone 13 users are experiencing touch sensitivity issues on iOS 15. There are several instances reported by users which include tap to wake, where the iPhone would not wake up or respond to touch and other instances are spread system-wide.