Apple released iOS 17.6 on July 29, and as is traditional, it has now stopped signing iOS 17.5.1, making downgrading to that version of iOS no longer possible. iOS 17.6 is now the only publicly released version of iOS available.
The iOS 17.6 software can be downloaded on compatible devices over the air by going to “Settings” -> “General” -> “Software Update.”
iOS 17.5.1 addressed a corruption bug that could cause deleted photos to reappear on an iPhone. The iOS 17.6 update addressed unspecified bug fixes and security updates.
Falling back to an older iOS build is often used by users who jailbreak their iPhones. Restoring an iPhone or iPad to a previous version of iOS can also sometimes be helpful for users who experience significant bugs after upgrading to the latest version of iOS.
