Following the launch of iOS 16.3.1, Apple will not allow iOS 16.3 signins anymore. After the release of iOS 16. 3. 1 on February 13, Apple has stopped signing iOS 16.
Apple stops signing iOS 16.2, following the iOS 16.3 update. Apple no longer signs to iOS 16. 2, the previous version of iOS, following the release of iOS 16.