Does anyone know how to force or make default for a 4G signal? It seems my phone, since the recent upgrade wants to resort to 3G most of the time here at home when it was always or mostly on 4G in the past. I've done the reboot (not the short quick version) and switching on and off to airplane mode, and I still get the problem. My wife's phone stays on 4G most of the time, yet mine doesn't. Any suggestions? Thanks!