Strange black screen (working phone)

Hi, yesterday I fixed up my client's Galaxy S22, I had to change the screen, I used an original one, a known working one however the strange thing was that the screen would stop working after putting together the phone but starting working again if the motherboard was just hanging out of the phone, what would you throw a look into to figure it out? I think it's something related to the motherboard or proximity sensor, as the thing would start going crazy in certain angles when the light would just go onto it.

I forgot to specify, I completly rebuilt the phone, screen, midframe and backglass, the phone had a literal hole trough the old screen

The screen won't show any image now, the phone is working, it vibrates, charges and sounds are coming from it (notifications and stuff)