What phone do you have?
What plan are you on?
Does your plan include data, or just talk & text?
When the phone sits idle and goes (maybe) though an update or not it will shut off and not restart until I do a hard restart pushing the buttons. Also, I noticed it will show a lightning bolt indicating it is charging but will not charge beyond a certain percentage for hours. Then when I unplug and plug back in it will charge. Both of these occur using the same charger and cord.