Had same trouble. All or nothing reception bars. Scheduled messages not sending. Calls and messages not coming through.
Dropped from 4G and now get reception, seems to be holding. Reception bars vary from three to four which seems more realistic(?) than all or nothing.
Hopefully this means the phone doesn't heat up so much, and that I can finally get at least a full day of battery life; these were other issues I've been having.
Doesn't seem like a fair solution though, to just drop off the 4G network.
I find myself wanting to go back to using my cheap old Samsung - it was 3G and reliable - not the way you want to feel with a shiny new piece of tech in your hand.