My wife's phone has recently developed a problem where she cannot make or receive a call without rebooting the phone. We cannot figure out any pattern to this, and it has only started recently. It may not occur for several days, and then it may occur every other day. I am assuming that there is some change in the settings or some app that's causing a problem since it's only recently, but I cannot figure out what it might be. I'm hoping someone has a solution.