I have an iPhone 7 and updated it to 14.2(?) a few weeks ago. It wouldn’t work while I was at home but when I was out, it worked fine. But then a few days ago it stopped working completely. It would only work on wifi. Finally got my lazy *** to the Apple store today. They sent it in to fix. They said it was my model that was an issue and they would fix it for free. If the issue was anything other than whatever they seemed to know- I’d have to pay for it. They gave me a loaner iPhone 7 phone which works fine with my sim. Yay! So hopefully it’ll get fixed and I can get my phone back in about two weeks. TL;DR: if you have an iPhone 7, go to an Apple store to get it checked. They just may fix it for free.