iPhone X screen starts flickering and iPhone shuts off

My iPhone X Display flickers and the iPhone turns off and starts to reboot, and after a few seconds this process repeats (so it is unusable at the time).

But if I press down on the upper part of the logic board (with all the connectors plugged in), it works like normal.

I have checked all the connectors because I assumed it might be a loose contact. I unplugged, checked and replugged everything, but without pushing down on the upper part of the logic board it won’t work.

Do you have any Idea how I could fix this problem?