My GPS froze after the 14.13 update. I dropped off my 3 at the service center yesterday morning and by the evening, it was showing the correct location on the app after having been stuck at my home address for the entire day. Either they already did something about it, or the GPS somehow fixed itself, or the geofence at the service center updated the cars location by a non-GPS method.
Service center said a hard reset where they pull fuses to completely power-down the system was one of the things they would try to fix it, which would explain why bringing it in was recommended.