The Device Logs from Local Run for both Android and iOS say:
flutter: Error querying CollectionReference<Map<String, dynamic>>(Support): [cloud_firestore/permission-denied] The caller does not have permission to execute the specified operation.
The Support collection is accessible by everyone (Firestore Rules) and the Test in Chrome Browser does return a value for the number of support ticket documents in that collection.
The App runs on iPhone, Android phone, iOS Simulator, Android Simulator, Test in Chrome browser
The App can connect to Firestore only on iPhone and the Test in Chrome browser.
The App cannot connect to Firestore on my Android phone, iOS Simulator, Android Simulator
The screenshot below shows that the app is loading (can render the login buttons) but not connecting to Firestore (circling loading icon where text would show as drawn from the Firestore database).