MySqlConnection.OpenAsync() не работает

public async static Task<User> CheckLogin(string login, string password)
{
    User user = null;
    string sql = @"SELECT 
                        id, login, password, first_name, middle_name, last_name
                    FROM
                        qrbd.user
                    WHERE
                        login = @Login AND password = @Password;";
    try
    {
        using (MySqlConnection con = new MySqlConnection(connStr))
        {
            await con.OpenAsync();
            using (MySqlCommand command = new MySqlCommand(sql, con))
            {
                command.Parameters.AddWithValue("Login", login);
                command.Parameters.AddWithValue("Password", Hash.GetHashText(password));
 
                using (MySqlDataReader reder = await command.ExecuteReaderAsync())
                {
                    while (await reder.ReadAsync())
                    {
                        user = new User
                        {
                            Id = reder.GetInt32(0),
                            Login = reder.GetString(1),
                            Password = reder.GetString(2),
                            FirstName = reder.GetString(3),
                            MiddleName = reder.GetString(4),
                            LastName = reder.GetString(5)
                        };
                    }
                }
            }
        }
        return user;
    }
    catch (Exception ex) 
    {
        throw new ApplicationException();
    }
}

command.Parameters.AddWithValue("@Login", login);

public async void Login(string login, string password)
{
       if (!string.IsNullOrEmpty(login) && !string.IsNullOrEmpty(password))
      {
            user = await MySQL.CheckLogin(login, password);
      }
}

public ICommand LoginComm { get { return new RelayCommand(OnLogin); } }
public void OnLogin() => model.Login(Username, Password);

private async void SaveWorkMeasureExecuted(object obj)
    => await SaveWorkMeasureAsync();

private RelayCommand _saveWorkMeasureCommand;
 
private async void SaveWorkMeasureExecuted(object obj)
    => await SaveWorkMeasureAsync();
private bool SaveWorkMeasureCanExecute(object obj)
    => SelectedWorks.Count > 0 && SelectedMeasure != null;
 
public RelayCommand SaveWorkMeasureCommand
    => _saveWorkMeasureCommand ??= new RelayCommand(SaveWorkMeasureExecuted, SaveWorkMeasureCanExecute);
 
private async Task SaveWorkMeasureAsync()
{
    try
    {
        List<int> positions = new List<int>();
 
        foreach (WorkDrawData work in SelectedWorks)
            positions.Add(work.IDDrawSpec);
 
        int counter = await _mainDA.SpecialDA.SetWorkMeasureAsync(SelectedMeasure, positions);
 
        ViewContext.Post(vc =>
        {
            foreach (int i in positions)
            {
                foreach (WorkDrawData work in Works)
                {
                    if (i == work.IDDrawSpec)
                    {
                        work.MeasureID = SelectedMeasure.MeasureID;
                        work.Measure = SelectedMeasure.MeasureName;
                    }
                }
            }
        }, null);
 
        string message = string.Format("Обработано записей: {0}", counter);
 
        _windowService.ShowInfoMessage(message, "Обновление данных");
    }
    catch (Exception ex)
    {
        _windowService.ShowErrorMessage(ex.Message, "Ошибка");
    }
}

public async void OnLogin() => await model.Login(Username, Password);

public IAsyncCommand LoginComm { get { return new AsyncCommand(OnLogin); } }
private async Task OnLogin() => await model.Login(Username, Password);

private RelayCommand _gplansEditDialogCommand;
 
private void GPlansEditDialogExecuted(object obj)
    => GPlansEditDialog(obj);
private static bool GPlansEditDialogCanExecute(object arg)
    => arg != null;
    
public RelayCommand GPlansEditDialogCommand
    => _gplansEditDialogCommand ??= new RelayCommand(GPlansEditDialogExecuted, GPlansEditDialogCanExecute);
 
private void GPlansEditDialog(object obj)
{
    // В зависимости от параметра команды выполняем что надо
    if (obj is EObject)
    {
        IGPlansDialogVM vm = _viewModelFactory.CreateViewModel<IGPlansDialogVM>();
 
        vm.CurrentEObject = SelectedEObject;
 
        _windowService.ShowDialog(vm);
    }
    else if (obj is GPReport)
    {
        int index = GPReports.IndexOf(GPReports.FirstOrDefault(r => r.GPlanID == SelectedGPReport.GPlanID));
 
        IGPlanEditDialogVM vm = _viewModelFactory.CreateViewModel<IGPlanEditDialogVM>();
 
        vm.EditGPlan = new GPlan
        {
            EObjectID = SelectedGPReport.EObjectID,
            GPlanID = SelectedGPReport.GPlanID,
            KKS = SelectedGPReport.KKS,
            GPlanName = SelectedGPReport.GPlanName
        };
 
        _windowService.ShowDialog(vm);
 
        if (vm.DialogResult == true)
        {
            GPReport report = new GPReport
            {
                EObjectID = SelectedGPReport.EObjectID,
                GPlanID = SelectedGPReport.GPlanID,
                KKS = vm.EditGPlan.KKS,
                GPlanName = vm.EditGPlan.GPlanName,
                TotalWeight = SelectedGPReport.TotalWeight,
                TotalLabor = SelectedGPReport.TotalLabor,
                ErectedWeight = SelectedGPReport.ErectedWeight,
                ErectedLabor = SelectedGPReport.ErectedLabor,
                RemainWeight = SelectedGPReport.RemainWeight,
                RemainLabor = SelectedGPReport.RemainLabor
            };
 
            GPReports[index] = report;
 
            SelectedGPReport = GPReports.FirstOrDefault(g => g.GPlanID == report.GPlanID);
        }
    }
}