Had to use Google Maps last night and the little blue triangle would not stay locked on the road. In the past, with Google Maps it would constantly follow me as I drive. It did not do that last night. This is a new iPhone 5S replacement. It seemed that it could not lock onto anything. I tried Apple's Maps and it was the same thing. Just performed a FULL factory reset and did not restore from a back up (which was a pain because I lost all my game scores) and it still is not resolved. While, the GPS navigation did follow me while driving on Apple's maps, it did not on Google. Google even said it is beta. I figured I would google how to calibrate the iPhone GPS. It said to do it with the compass, which I have done. Will test again later. I am just curious if the GPS inside the phone can be off, or defective?