Widget with relative route not displayed in page where the w

I have an MVC widget with Index method that has RelativeRoute attribute, but when calling the route relative to its page, the content is rendered alone and ignored the template/page, which is against what is mentioned in this docs (docs.sitefinity.com/feather-use-the-relative-routes-api) 

SiteHeader and SiteFooter placeholders are not rendered!!!

Knowing that I am using pure MVC mode,  cshtml layout, and controller's method is: 

[RelativeRoute("param1/param2/param3")]
        public ActionResult Index(string param1, string param2, string param3)

       
          //
            return View("Default");