Yep same issue, since Jan. 10th after I did latest update. After 15 calls to T-Mobile and a store visit they finally concluded it was my iPhone 8+. I tried EVERY online trick 20 times nothing worked. Finally got the idea to put sim card in my old iPhone 6 and that phone works fine. I just tried a factory reset and that did not work either. Can't believe Apple is not coming forward and at least acknowledging the problem, I really don't like putting my life in danger going to stores during a pandemic to try and fix an issue they know about, but will not acknowledge yet.