I’ve had the same issue with my iPhone 7. Day 3 now. I’m on Verizon and nothing has remedied the problem. I reset network settings about a thousand times, forced a reinstall of 14.0.1, did a full system restore and then went to Verizon where they changed out my SIM card. All were unsuccessful. It works on WiFi and will once in awhile grab a cellular signal after I reboot several times. I just wanted this phone to get me through until the 12 comes out. Please fix it.