Did you launch a complain thru the Apple Support hotline or website?

Recently a friend of mine having issue with his Iphone 11 signal, he called Apple Support and they guide him to capture log from the phone for analysis. Said could be firmware issue and if true will fix in the upcoming release.

Not the Apple Authorised seller at shop as those will check hardware high level issue but online/ phone usually Apple experts on iOS.

Came back here after 2 months seem like iPhone 11 is having a serious bug that LTE will drop to EDGE. Maybe ios16 screwed up the hardware of iPhone 11. Another friend faced the issue called Apple Support went thru some troubleshooting and testing the. the guy said probable cause is hardware failure and replace hardware for my friends foc.