Following the release of iOS 13.1.2 last week, Apple today stopped signing iOS 13.1, meaning downgrading to this version of iOS is no longer possible.
Apple last Friday stopped signing iOS 12.4.1, iOS 13.0, and iOS 13.1.1, but continued signing iOS 13.1 until today.
iOS 13.1.2 was a bug fix release that quickly followed iOS 13.1.1, which primarily addressed issues with battery drain, Siri,...