Ok that is from my memory, so I can make a mistake. Something wrong with your time settings when your phone switches from and to LTE. But you already know that don't you. Problem occurs on Verizon towers that your phone connects to. No easy fix, but from rumors if Verizon or Apple know what tower is affected they can ask their engineering to update software on that particular tower. As long as you using LTE, unless software on the tower is updated, there is no fix for the phone. So if you don't travel much report those towers. If you do travel a lot, enjoy the ride.