Screen failure in lower left corner only when assembled

Hey,

I have pretty weird issue with my iphone 7:

I bought a new screen since the old one was cracked and installed it. before assembly I tested the screen and everything including 3d touch worked. but after assembly, 3d touch didn't work in the lower right corner.

Additionaly when pressing firm on the display in that area the screen shows some flickering. I thought I damaged the screen while assembling, but here is the weird part:

when I pull the screen a few centimeters out of the phone and support it with my finger it works again. I have tried this about 5 times now. assembled not working. dissambled yes.

has anyone any how idea why this is ?

Could this be an issue with the metal shield on the back on the screen. it got very little bend when assembling on the new screen. I have taken it of and again 2 times as well.

The only other thing I could think of would be that the display cables are getting somehow squished when putting it together. But I am really confused here. Hope somebody can help.