Apple No Longer Supports iOS 15.4, Restricts Downgrading from iOS 15.4.1

Applestopped supporting iOS 15.4 just a week after releasing iOS 15.4.1. Apple no longer supports iOS 15.4, restricting users from downgrading their iPhone models to earlier than the latest iOS version and directing them to update to iOS 15.4.1.
Apple has started regularly stopping support for older versions of iOS builds to prevent incidents of jailbroken devices. When an iOS version is “unsigned,” users cannot officially downgrade or upgrade their devices to that version.
The iOS 15.4 update was released last month along with iPadOS 15.4, macOS Monterey 12.3 and watchOS 8.5. It was at this time that he introduced the expected feature of unlocking the iPhone using Face ID while wearing a mask. However, the update also caused “rapid battery drain” issues for some iPhone users with the release of Apple’s iOS 15.4.1.
Apple also released a fix for the “zero-day” vulnerability in iOS 15.4.1, found in the AppleAVD media framework. The company also announced that it was aware that the vulnerability may have been actively exploited by attackers. This means users have a solid reason to update their devices to iOS 15.4.1.
As MacRumors explains, Apple has stopped signing (supporting) iOS 15.4, as well as tvOS 15.4 and HomePod Software Release 15.4. iPadOS 15.4 is also no longer signed/supported by the company.
Apple only offers a few iOS version signatures at a time to prevent jailbreaks and restrict users from downgrading to older versions. This diversity also serves to encourage users to use the updated operating system on their iPhones with the latest security fixes, as they cannot revert to an older version. It is possible to limit security problems and third-party attacks. However, some people do not find the process of stopping signing older software versions helpful, as it restricts them from reverting back to an existing experience if they are dissatisfied with the features offered in the new version.
Apple iOS 15.5 Developer Beta Released
Earlier this week, Apple released the first developer beta of iOS 15.5. External purchases include the Apple Classical app and an updated Wallet app, as well as references to supporting apps.