My unlocked and rooted (latest stock ROM) 8t has never had network issues, but this morning it suddenly can't establish a cellular connection using my US Mobile Dark Star SIM, which works fine in my son's old iPhone. The network connection just keeps turning itself on and off, the APN(s) keep disappearing, and network settings say there's no carrier. I also can't set anything manually and make it stick.All I can think of now is to unroot (done, no change), then relock the bootloader...Read more