Hi Thomas! I'm unsure if you are still facing this issue and if you are building an app out of Flutter. In the case of the app my team is building using Flutter, we have been seeing a trend that whenever we make some changes to the code in android and iOS versions, the GoogleService-info.plist file gets corrupted. We need to download this file again from our Firebase dashboard and then replace the existing GoogleService-info.plist with a new one. That immediately solved issues at our end. My team is also using XCode 13.2.1 at the moment. Hope this is helpful! Thanks, Desi Rocket Scientist