I am having wi-fi issues with my new iPhone 5. As of last night, my wi-fi at home was working great on my iPhone, however, now here at work, it will load the wifi, give me the checkmark and get the little Wi-Fi bar next to "AT&T". It will work for a few minutes and then it will shut off and go back to "LTE". Is anyone else having this issue? Anyone find a way to resolve it?