Image: Apple
Apple has stopped signing iOS 17.3, meaning downgrading to this version from the newer version iOS 17.3.1 is no longer possible. If you're running iOS 17.4 beta, you can downgrade to 17.3.1 but no longer to 17.3.
Released on January 22, iOS 17.3 brought notable features like Stolen Device Protection for iPhones. It requires Face ID/Touch ID for actions like changing the Apple ID password or disabling Find My. It also introduced collaborative Apple Music playlists. Meanwhile, the newer iOS 17.3.1, released on February 8, addressed a bug causing unexpected text duplication or overlaps while typing.