Apple has stopped allowing downgrading to iOS 17.6.1 a week after iOS 18 was released to the public.
iPad and iOS users can no longer go back to version 17.6.1, with the exception of M4 iPad Pro users. Apple routinely stops signing older software once newer ones have debuted, and to stop users from using outdated software. There’s also a matter of privacy and security as well, as newer software typically contains bug fixes and improvements, patching security vulnerabilities in the older versions.
iPad Pro users with the M4 chip can still downgrade to iPadOS 17.6.1 as iOS 18 has been known to cause problems. After updating to iPadOS 18, some users have reported that their devices would not turn on, with Apple acknowledging the issue and currently working on a fix. The only option for iPhone users is to downgrade to iOS 17.7.
