IOS 16 knocked out cellular service on my iPhone 12 Pro Max. It's been two days now. I have talked to apple support (up to senior level tech) about four times, and they can't fix the issue. My carrier (Xfinity Mobile) gave me a free new Sim card. That didn't fix it. First Apple blamed Xfinity Mobile, and then Xfinity Mobile blamed Apple. I just hung up with senior tech for Apple. We were on the Applewatch phone for about an hour and a half. She couldn't resolve the issue. She says I need to go to the Apple store now as a walk-in. I'm heated! No one has offered to replay the phone (which is not even two years old and I never had an issue with it until I tried to update it with the IOS 16 system). I'm highly frustrated and about to look at Apple differently (I own an iMac, iPad, iPhone, and Applewatch. All Apple!!!).