Swashbuckle Swagger UI does not show parameters description

Package version 6.0.0-beta902

Examples :

public class TestModel
{
    /// <summary>
    /// This is description of Name
    /// </summary>
    public string Name { get; set; }
}

public IActionResult HelloWorld(TestModel model)
{
    return Content("hello " + model.Name);
}

Why Swagger UI does not show Name parameter description ?