First of all, thanks Rick for putting us on the right track. Now, I've had this problem on my device, and so I opened it and tested, seems that your first solution (the mesh) IS the correct one. The other (flexible) connector on the PCB (the one that you updated to be it), is possibly not related to GPS. Just to make some order, they BOTH connect to case metal (ground) which is very strange as I can not think why or how would it be used as an antenna. But!, powering the phone while opened, testing several pins which connects to the back, only 1 was found to be the pin for the GPS receiver. This was tested with a thin wire connected and watching the reception on GPS test app. Tested several times, each time yielded same result. Only the connector that mates with the mesh on the case (top right of back case when looking at it while phone opened) gave almost instant lock and strong reception. I'm including photos with remarks to make it hopefully clear: Here you see the mesh in the top right, the other...
It helped me to fix my focus ring. In my case the teeth on the ring were not damaged, but a small piece of some broken plastic was blocking the ring from moving smoothly.