It may happen that you receive an error message even though your Google Authenticator is set up correctly. The reason could be that the internal time of your Google Authenticator is not synchronized. A re-sync of Google Authenticator is fairly straight forward and will not change your device’s Date & Time Settings.
- Go to the main app menu (three vertical dots).
- Tap Settings.
- Tap Time correction for codes.
- Tap Sync now.
- Open the Settings app on your iPhone home screen.
- Tap General.
- Tap Date & Time.
- Disable Set Automatically option and re-enable again.
- Reboot your device.