I installed the One UI 6.1 upgrade, which was released on 1 june 2024, on my S21 Ultra 5G (SM-G998U1). As soon as I installed the upgrade it got restarted but disabled the touch screen. I cannot use the touch at all. 

The weakness of the Samsung system has shocked me. I wonder if this update was already tested for safety or Samsung just released it with extreme carelessness. 

I performed the following procedure to get my phone work but could not succeed

1. Restarted (by pressing power+down volume)

2. Clear the Cache (going into the setup)

3. Factory Reset (by losing all my valuable data)

Note: Samsung should come forward and advise a solution to a problem they created. So they are responsible for fixing it in any way.