Always searching for GPS and calls ending before connecting

[Deslan]

My Sony Xperia can never give me directions when I need it - constantly searching for GPS. It finds it either after 30 minutes or after a reboot. Making phone calls is a problem - occasionally it ends the call before even connecting. I dial a number and (after a delay to go to the dialling screen) it says call ended. Only solution here is to reboot. This is frustrating. Yes I have done a factory reset twice and I've tried different sim cards as well.
Please assist

[Trubo_XL]

For GPS, that's Sony's fault for not updating the root certificate...

For Calling, there maybe some problem going on in your phone since you did mention Repair The Firmware twice...
I dont know what I can recommend...