It could be that the time on your Google Authenticator app isn't synchronised properly.
To make sure you are using the correct time:
- Switch to the main menu in the Google Authenticator app.
- Tap More settings.
- Tap Time correction for codes.
- Tap Sync now.
On the next screen, the app will confirm that the time has been synced and you should now be able to use your verification codes to sign in. Only the internal time of the Google Authenticator app will be synced. This will not affect the date and time settings on your device.