Controller does not pass route value to View ASP.NET MVC

Question

Based on my previous question: Problem with page return according to C profile# When accessing the system with another user with the "ADMIN" Profile, the controller’s return does not fall into the view and does not call the route of the page that should return. Already accessing with the "System Administrator" works. What might be going on ?

public ActionResult LogOn(FormCollection f, string returnUrl)
        {
            Conta user = new Conta();
            ContaModels atrrConta = new ContaModels();
            atrrConta = user.RetornaUser(f["login"]);
            if (user.AutenticaUser(atrrConta, f["senha"]))
            {
                //Rotina para autenticar usuario
                if (returnUrl == "" || returnUrl == null)
                {
                    returnUrl = "../CalendarioAlertaSMS";
                }
                System.Web.Security.FormsAuthentication.SetAuthCookie(f["login"], false);

                Session["PERFIL"] = atrrConta.Ide_Perfil;
                if (Session["PERFIL"].ToString() == "ADMIN")
                {
                    returnUrl = "../PainelAdm";
                }

                return Redirect(returnUrl);
            }
            else {
                ViewBag.Message = "Login ou senha inválidos.";
                return View(); 
            }
        }