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);
        }
    }

Having this problem too - did you manage to fix it? @wheels