This is a small Ionic-Angular project to reproduce this issue: ionic-team/capacitor#7631

It consists of a blank Ionic app (created with ionic start) with Firebase Auth added to it. When executed, the app displays a "Sign in anonymously" / "Sign out" button and displays the uid of the logged-in user.

Setup:

• Create a Firebase project (https://console.firebase.google.com/) and enable Authentication on it. Then, in the "Sign-in method" tab, add the "Anonymous" sign-in provider.
• Clone the project git clone https://github.com/ddx001/ios-problem.git
• Configure the project to use Firebase by updating the files in src/environments with your new project configuration.
• Run npm install
• Run ionic serve
• Open the app (http://localhost:8100) in a browser and click the "Sign in anonymously" button.

It should Sign in and display the uid of the logged-in user. That's the expected behavior.

Reproduce the bug:

• Build the app ionic build --prod
• Copy to iOS npx cap sync ios
• Open the project in Xcode npx cap open ios
• Run the project on a device.

Now it doesn't work. That's the bug!

Error messages:

nw_application_id_create_self NECP_CLIENT_ACTION_GET_SIGNED_CLIENT_ID [80: Authentication error]
Failed to resolve host network app id
Warning: -[BETextInput attributedMarkedText] is unimplemented
KeyboardPlugin: resize mode - native
⚡️  Loading app at capacitor://localhost...
⚡️  WebView loaded
⚡️  [log] - heartbeats undefined
⚡️  [log] - heartbeats undefined
⚡️  To Native ->  App addListener 103483311
⚡️  To Native ->  Keyboard getResizeMode 103483312
⚡️  TO JS {"mode":"native"}
Invalidating grant <invalid NS/CF object> failed