ASCredentialProviderExtensionContext completeRequestWithTextToInsert:completionHandler: sometimes fails to return text

completeRequestWithTextToInsert is used to return text into an arbitrary textfield via the context menu AutoFill/Passwords from a 3rd party password manager (or presumably the Passwords App) in iOS 18.

While testing this feature in the debugger, it would often fail on the first invocation. It also appears to happen intermittently in the released app extension. Subsequent testing using the Passwords App shows it too may fail to return a value.

I have confirmed this behaviour is repeatable with the Passwords App on an iPhone running iOS 18.3.1

1. Reboot the iPhone.
2. Show the App Library, and right click Autofill.
3. Select Passwords
4. Select Passwords (App)
5. Select a password.
6. Nothing will be inserted (intermittently).

Feedback assistant report: FB16788563