Same issue on my phone. I have iPhone 8 and had a bout with No Service starting from quarantine in March when i switched to WFH. In April, after trying to address it multiple times, i purchased a Verizon Network Extender for a few hundred and after much confusion with several Verizon reps, was able to get this to work properly. it worked like a charm from April through even moving across the country for a month (took it with me) and returning to the east coast in August. Around that time I made what now appears to be the very poor decision of upgrading to ios 14 at which point it stopped working. Now i'm back to "No Service." i've tried everything, except for wiping the phone because i haven't taken the time to figure out how to back it up properly (without buying data storage from someone). To be clear ALL of the solutions work...for a very short period of time. They give me a full 4 bars before switching back to No Service within seconds or a minute or two. And i've tried every combination of turning roaming on/off, switching to 3G, turning VoLTE off (which i can't BTW if 4G is enabled, it's permalocked on). I upgraded to 14.1 and it did not help. i'm seeing in your comments that 14.2 or .3 won't work either. This is so frustrating. I can't make consistent phone calls, nor receive texts from people who don't have iphones. There are days that i restart or put on/off airplane mode 100 times, just to push texts through. When are apple or verizon going to fix this???