Unfortunatly the problem is back again for me. It worked pretty well during the day time but now it won't receive calls anymore. This is the 8th day I've had this phone, still have 6 more days to return it. I'll try the suggestion "wilcre" offered, if that does not work the phone is going back. Too bad, it's such a nice phone but won't do the basic phone functions well. Don't know if the issue is with the way LTE works and with other phones as well or just HTC One x+