Unity Authentication - SignInWithGoogleAsync Throws Permission Denied

I'm sure I am missing something silly but when I pass the google id token to Unity Authentication I get the errors:

[Authentication]: Request failed: 401, {"title":"PERMISSION_DENIED","detail":"validation failed","details":[],"status":401}

WebRequestException: {"title":"PERMISSION_DENIED","detail":"validation failed","details":[],"status":401}

Below is my code, any help appreciated:

  async void Awake()
     {
         await UnityServices.InitializeAsync();
         InitializePlayGamesLogin();
     }
 
     void InitializePlayGamesLogin()
     {
         PlayGamesPlatform.Activate();
     }
 
     // Call when login button is pressed
     public void LoginGooglePlayGames()
     {       
         Social.localUser.Authenticate(OnGooglePlayGamesLogin);
     }
 
     //Check login success
     async void OnGooglePlayGamesLogin(bool success)
     {
         if (success)
         {
             // Call Unity Authentication SDK to sign in or link with Google.
             string idToken = PlayGamesPlatform.Instance.GetUserId();
             await SignInWithGoogleAsync(idToken);                          
         }
         else
         {
             Debug.Log("Unsuccessful login");
         }
     }
 
     async Task SignInWithGoogleAsync(string idToken)
     {
         try
         {
             await AuthenticationService.Instance.SignInWithGoogleAsync(idToken);
             Debug.Log("SignIn is successful.");
             //if sign in successful turn off login screen.
             loginScreen.SetActive(false);
         }
         catch (AuthenticationException ex)
         {
             // Compare error code to AuthenticationErrorCodes
             // Notify the player with the proper error message
             Debug.LogException(ex);
         }
         catch (RequestFailedException ex)
         {
             // Compare error code to CommonErrorCodes
             // Notify the player with the proper error message
             Debug.LogException(ex);
         }
     }