In my case (Flutter 3.35 on macOS), it was not a Firebase outage. It was a combination of package version and macOS network permissions / entitlements.

1️⃣ Update Flutter & Firebase packages

First, make sure you’re on a recent Flutter and Firebase version:

flutter upgrade
flutter pub upgrade

And in pubspec.yaml use the latest versions of:

firebase_core: ^latest
cloud_firestore: ^latest

Then:

flutter pub get

2️⃣ Add network permission in macos/Runner/Info.plist

In macos/Runner/Info.plist, add:

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsArbitraryLoads</key>
    <true/>
</dict>

3️⃣ Update macOS entitlements

Both of these files need network client permission:

• macos/Runner/Release.entitlements

• macos/Runner/DebugProfile.entitlements

Add:

<key>com.apple.security.network.client</key>
<true/>

4️⃣ Clean and reinstall pods

Finally, clean and rebuild:

flutter clean
rm -rf macos/Pods macos/Podfile.lock
pod install
flutter run


Hope this helps someone facing the same issue Thanks