I have encountered a possible compatibility issue with apps built using Xcode 27.1 and running on iOS 15.8 devices.
Development environment
- Xcode 27.1
- macOS 27.2
- Build Configuration: Debug
- iOS Deployment Target: 15.8
Test device
- iPhone 7
- iOS 15.8
Observed behavior
When running an app built with Xcode 27.1 on an iPhone 7 running iOS 15.8, button interactions sometimes fail to update the user interface.
The button press animation is displayed, indicating that the button is being interacted with. However, the expected UI state changes are sometimes not reflected, even after repeated taps.
This behavior affects multiple buttons, rather than a single specific button.
Comparison
- An IPA built with Xcode 26.2 works correctly on the same iPhone 7.
- An IPA built with Xcode 27.1 exhibits the UI update problem.
- The app runs correctly in the Xcode 27.1 Simulator.
Question
Is there a known compatibility issue in Xcode 27.1, its Swift compiler, or the iOS SDK that could cause SwiftUI UI updates to fail on iOS 15 devices?
Although iOS 15.8 is available as a deployment target, I would like to know whether apps built with Xcode 27.1 are expected to work correctly on iOS 15 devices.
Has anyone encountered similar behavior?