Today, Apple released iOS 15.1.1 (version number 19B81). The focus of this fix is the call drop problem encountered by iPhone 13 and iPhone 12 users.
Currently, users can download it via OTA on compatible iPhone and iPad models.
According to Apple’s release notes, iOS 15.1.1 fixes the call drop problem on iPhone 12 and iPhone 13, as well as regular bug fixes. Apple did not provide specific release notes for iPadOS 15.1.1.
Apple’s previous version, iOS 15.1 build 19B74, was released on October 25. This version added support for SharePlay and vaccine card input in Apple Wallet. This is also the first bug fix version after the update was released.
Many users called after seeing the update of this version of Apple. Before, they always felt that sometimes dropped calls were caused by nearby signal problems.
Unexpectedly, it was a software problem, which showed that it could not be dialed after the connection was dropped, but in fact, it could, in short, it was dropped.
If you also have this problem, then update and upgrade as soon as possible.
Gelo 
Mike Lee-111 
A P 
Blair