Q: iPhone 6 Plus Crashing or Locking up in Low Signal/No Signal Areas

Has anyone had a problem where the phone becomes unresponsive, the home button doesn't work and nor does the sleep button, when in a low signal or no signal area. In my home I have a couple of bars of signal in the living room and if I'm using an app and walk out ot the hallway as the signal drops off the phone becomes unresponsive and either remains on the screen it was, on a black screen or crashes and reboots.