I am pretty sure, that it is the module because replacing it helped for a few months. There are forum entried where users are warned to handle the phone while it’s charging because the wiggling plug causes too much deformations on the connector. I think, this shouldn’t matter but we are talking about the second generation of a completely new mobile phone concept. So it’s a plausible thought.
Your friend’s bottom module might have had more issues than just charging or it’s really a connection issue with yours. Did you check the connector pads on the backside of the display? They aren’t solid metal. I noticed that the conductive surface scratches away easily, so I put conducting lacquer with silver on them.
As for the next steps, I want to understand and repair whatever may be broken here. Could be a conductor path or a solder joint.
After that, I want to solve the issue for good. Dreaming of an induction charger. ^^