App Clip Invocation Issues on iOS 18 and iOS 18.1 - NFC and QR Invocation not working for Default App Clip Experience

We have identified an issue on iOS 18 and iOS 18.1 (developer beta) where App Clips invoked via NFC or QR codes without a pre-configured Advanced App Clip experience (aka they should be using the Default App Clip Experience) are not functioning as expected. This issue is specific to iOS 18, as the behavior works correctly on iOS devices running 17.x.

Steps to Reproduce:

1. Set up two scenarios:
   • One scenario where an App Clip has a pre-configured advanced app clip experience (with metadata such as title, subtitle, image).
   • Another scenario where the App Clip is invoked without any pre-configured experience (should use the default App Clip experience).
2. On an iOS 18 or iOS 18.1 device:
   • For the default App Clip experience (no pre-configured advanced app clip experence):
     • Scan the NFC tag when the phone is locked.
     • Scan the NFC tag when the phone is unlocked.
     • Scan the QR code.
   • For the pre-configured App Clip experience:
     • Perform the same tests (NFC and QR code scans).
3. Test the same scenarios on an iOS 17 device for comparison.

Expected Behavior:

• For default App Clip experience invocations (NFC or QR):
  • Scanning NFC or QR should still trigger the App Clip card, even without metadata or a pre-configured advanced experience, on both locked and unlocked devices.
• For pre-configured Advanced App Clip Experence invocations:
  • The App Clip card should display correctly with the configured metadata and behave as expected on both locked and unlocked devices.

Observed Behavior on iOS 18 and iOS 18.1:

• For default App Clip experience invocations:
  • When scanning the NFC tag on a locked device, an error message is shown - e.g., "App Clip Unavailable" or "The operation couldn't be completed. (CPSErrorDomain error 2.)" .
  • When scanning the NFC tag on an unlocked device, the system redirects straight to the web browser instead of displaying the App Clip card (or even the normal NFC top of screen push notification style thing)
  • Scanning the QR code also prompts the user to open the web browser similar to the experience of scanning a non app clip QR code, skipping the expected App Clip experience.
• For pre-configured Advanced App Clip Experence invocations:
  • The App Clip behaves as expected, showing the correct card with metadata and functioning properly on both locked and unlocked devices.

Notes:

• The issue is only observed on iOS 18 and iOS 18.1, while the expected behavior is working fine on iOS 17.
• This may indicate a regression or change in behavior introduced with iOS 18 that affects App Clip invocations that do not have a pre-configured experience.