iPhone 8. I am also facing the same problem. After updating to iOS14, there was no network signal. I tried every suggested ways but nothing did work. I also did reset. Later on updated to iOS public beta 14.2 but problem is still there. Most of the time shows no service, some times it shows strong signal but can't call or receive call, and no mobile date. It's just a toy for kids and this kind of service not expected from apple.
I just found that in settings------>Phone then nothing is working. Cant change call waiting and even show my caller ID doesn't even open. Apple should solve the issue. iOS 13.7 was very smooth and there was no problem.
Sreedam
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