Following the release of iOS 13.2.2 on November 7, Apple has stopped signing iOS 13.2, which means downgrading to iOS 13.2 is no longer possible.
iOS 13.2 was a major update that brought support for AirPods Pro, added new emojis, and introduced Deep Fusion support for the iPhone 11 and 11 Pro.
Apple routinely stops signing older versions of software updates after new releases come out in order to encourage customers to keep their operating systems up to date.
iOS 13.2.2 is the current public version of iOS. iOS 13.2.2 is a bug fix release that addresses an issue that caused apps running in the background to unexpectedly quit, leading to background apps refreshing more often than normal.
The update also fixes a few other bugs with cellular connectivity, cellular data, Safari, and more.
Developers and public beta testers can also download iOS 13.3, an upcoming update that introduces Communication Limits for Screen Time and a handful of other tweaks and changes.
https://www.macrumors.com/2019/11/14/apple-stops-signing-ios-13-2/
