Shortly after Apple rolled out its iOS 17.3 beta 2 update, the company was forced to suspend the update process as some users reported bricked iPhones after applying the new version of the OS.
Apple even issued an official statement that the iOS 17.3 beta 2 version of the software “prevented a small number of devices from starting up”. Some believe that the bootloop issue is related to the Back Tap gesture, as only users who have disabled the feature are having trouble with their iPhones.
Those affected, however, have a rather easy fix to solve the problem. You just have to enter Recovery Mode and roll back to the previous version of iOS and wait until Apple releases a more stable version of iOS 17.3.
Source