aaApi_Login() returns error 55515: Invalid user name and password combination

I am trying to connect to a customer server/datasource with credentials that were provided via the customer.  I am able to login via ProjectWise Explorer with no issues.  If I use the same exact Server/Datasource , username and password in the api aaApi_Login(), I get the error 55515: Invalid user name and password combination

I have asked the customer if they are using any of the options in the dmskrnl.config, SSO, STS, DMS and I am waiting on a reply. 

I added info level logging and saw the error 11-11-20 14:52:11.458 [21] TRACE - InternalAuthenticator - Internal Authenticator token invalid in the file BeLicSvc.Log around the time of test.  My test program is below.  I have tried both aaApi_Login() and aaApi_Login3() with same error results.  Please let me know if you have any suggestions on:

- how to solve.

- how better to diagnose if not.  Questions for the the customer server environment, better logging techniques.

Thanks in advance - Mandi

        public bool Login(string user, string pass, string dsName, Action<string> log = null)
        {
            bool success = false;;
            try
            {
                ProjectWiseAPI.aaApi_Initialize(0); //AAMODULES_ALL
                ProjectWiseAPI.aaApi_InitializeModules(0);

                Guid userID = new Guid();

                lock (_lockLogins)  //lock until the login finishes.
                {
                    log($"Logging in as {user}");

                //       success = ProjectWiseAPI.aaApi_Login3(0, dsName, user, pass, "", ref userID);
                    success = ProjectWiseAPI.aaApi_Login(ProjectWiseAPI.DataSourceType.Unknown, dsName, user, pass, "", true);
                    if (success)
                    {
                        _loggedIn = true;
                        _user = user;
                        _dsName = dsName;
                        _dsType = -1;

                        ProjectWiseAPI.aaApi_GetCurrentSession(ref _session);
                        success = true;
                    }
                    else
                    {
                        int err = ProjectWiseAPI.aaApi_GetLastErrorId();
                        string msg = ProjectWiseAPI.aaApi_GetLastErrorMessage();
                        string det = ProjectWiseAPI.aaApi_GetLastErrorDetail();

                        log($"Logging error {err} - {msg} - {det}");
                    }
                }
            }
            catch (Exception ex)
            {
                log(ex.ToString());
            }
            return success;
        }