Power/ volume butom not working

Hi, i have got my P30 back from repoair/ they have replaced screan but after 2 days power buttom stopped working. same as volume buttoms.

What can be cause of it?

I have asked frend to take a look on it and after he took off topo cover he noticed main board on top left corner where screw is going is craccked, is posible that this can be main reason for it?