Is your phone in a case with a magnet to either keep it closed or wake the phone? If so that can cause a seemingly dead to input portion of the screen. If using safe mode works, try clearing the phone's cache partition rather than a factory reset to begin with
Then try disabling any third party apps one by one to see if the portion of screen affected starts working again. If that doesn't work and you cannot find the culprit a factory reset may be your only option. I'd backup all your personal files including photos and videos shot with the phone first before doing anything else.
@antikythera wrote: Then try disabling any third party apps one by one to see if the portion of screen affected starts working again. If that doesn't work and you cannot find the culprit a factory reset may be your only option. I'd backup all your personal files including photos and videos shot with the phone first before doing anything else.
This sounds like a common problem, so it is something related to the update. I am not factory resetting my phone for a stupid problem from Samsung -- how can they force my phone to become nonfunctional and expect me to fix it only by trashing my phone content?
