Just got back from AT&T, got a new sim, finally got a signal, got home and the dreaded no cell, you need to update blah blah blah. Reinstalled 14.2 after wiping completely and after restoring my backup, behold, no signal but wifi. I know it's a baseband problem, if you look at modem firmware under general in settings, it is BLANK. So, something is corrupting the baseband firmware. All this is on iPhone 7, I can put my sim in my iPhone 6 and have no problems but it is on 12.4.9.
Disgruntled
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
Post
Replies
Boosts
Views
Activity
After a clean wipe and restore, I get a modem firmware finally and I get att signal (brand new sim after store visit), works for about 18 hours then tries to update cellular again and I am back where the phone uses WiFi only. I guess I could just continue these long painful restores every 18 hours so I can use my phone as a phone.