Hello I am using a Galaxy Note 8. Since this morning I noticed that the top of my screen does not respond to my fingers any more. I can't do any action implying the top of the screen nor matter the app. Meanwhile it respond correctly when I use the SPen.
I would give this a try to see if it works in safe mode follow the instructions below
Safe mode allows you to turn on the device with third-party apps disabled. Then you can easily uninstall apps that may be causing a conflict or software problem.
Have you tried to refresh the entire phone by turning off the phone for 30 seconds. Turning back on if that doesn't work remove you finger touch security and start over. If that doesn't work either you will have the reset your phone but not factor reset