Iphone 12 mini - the touch still does not work correctly

Hello

Yesterday I picked up my 12 mini. Configuration, mandatory update to iOS 14.2 and ... touch still doesn't work as it should.

While holding it in my hand I did not notice any major problems, sometimes something "won't work" but it may be a matter of getting used to the touch panel. The problem begins when I put the phone on a flat surface. The most interesting thing is that, when I click or slide with the top of the finger it works. Unfortunately, when I try to touch it with a full fingertip (in other words, using a "flat touch") or when I try to do this with the other side of the finger, the screen practically does not respond to launching the application or moving the screen.

The phone, of course, packed in a case and with a protective glass.

Today I observed that with connected charger everything works ok, even when phone is on the flat surface. I can't understand that...

Has anyone noticed such a problem after update? Should I have the phone serviced?