Our 12.0.0 version of the iOS SDK released on Sept 12 2019 addressed known issues with iOS 13. We're currently on 12.1.2 and have made even more stability updates as well as Airship feature updates. If you are having issues receiving push notifications on your device you should upgrade to the most current version.
Cocoapod Page: https://cocoapods.org/pods/UrbanAirship-iOS-SDK
Technical Support Engineer
Airship | Portland