Redirect with session doesn't send success or error

I am on Laravel 5.6

I try to send success with session to show some success messages.

return redirect('templates')->with('success','Template added successfully');

It used to work perfectly. However, it stopped working now and I couldn't find the reasons why.

When I dd(redirect('templates')->with('success','Template added successfully');) I see success message inside it.

RedirectResponse {#438 ▼
  #request: Request {#43 ▶}
  #session: Store {#279 ▼
    #id: "9Qcvbynta2B3yrDPDGGj2UhPTjDsCgn1857UlQM0"
    #name: "laravel_session"
    #attributes: array:5 [▼
      "_token" => "ngzN7cWaJIlYrQsCmfSdapbT1UnCJ7jxuld3VCeP"
      "_previous" => array:1 [▶]
      "_flash" => array:2 [▶]
      "login_web_59ba36addc2b2f9401580f014c7f58ea4e30989d" => 6
      "success" => "Template Added Successfully"
    ]
    #handler: FileSessionHandler {#280 ▶}
    #started: true
  }

But I try to read it in blade it doesn't show anything at all. As I said it used to work perfectly.

@if (\Session::has('success'))
    sdfsdf

    <script>
        window.onload = function () {
            toastr.success("{{ \Session::get('success') }}");
        }
    </script>
@endif 

I am thinking of my recent changes I put this 3 to middleware in kernel

        \App\Http\Middleware\EncryptCookies::class,
        \Illuminate\Session\Middleware\StartSession::class,
        \App\Http\Middleware\LimitDemoUser::class,

This is my full Kernel.php

<?php

namespace App\Http;

use Illuminate\Foundation\Http\Kernel as HttpKernel;

class Kernel extends HttpKernel
{
    /**
     * The application's global HTTP middleware stack.
     *
     * These middleware are run during every request to your application.
     *
     * @var array
     */
        protected $middleware = [
            \Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class,
            \Illuminate\Foundation\Http\Middleware\ValidatePostSize::class,
            \App\Http\Middleware\TrimStrings::class,
            \Illuminate\Foundation\Http\Middleware\ConvertEmptyStringsToNull::class,
            \App\Http\Middleware\TrustProxies::class,
            \App\Http\Middleware\EncryptCookies::class,
            \Illuminate\Session\Middleware\StartSession::class,
            \App\Http\Middleware\LimitDemoUser::class,


        ];

    /**
     * The application's route middleware groups.
     *
     * @var array
     */
    protected $middlewareGroups = [
        'web' => [
            \App\Http\Middleware\EncryptCookies::class,
            \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
            \Illuminate\Session\Middleware\StartSession::class,
            // \Illuminate\Session\Middleware\AuthenticateSession::class,
            \Illuminate\View\Middleware\ShareErrorsFromSession::class,
            \App\Http\Middleware\VerifyCsrfToken::class,
            \Illuminate\Routing\Middleware\SubstituteBindings::class,




        ],

        'api' => [
            'throttle:60,1',
            'bindings',
        ],
    ];

    /**
     * The application's route middleware.
     *
     * These middleware may be assigned to groups or used individually.
     *
     * @var array
     */
    protected $routeMiddleware = [
        'auth' => \Illuminate\Auth\Middleware\Authenticate::class,
        'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
        'bindings' => \Illuminate\Routing\Middleware\SubstituteBindings::class,
        'cache.headers' => \Illuminate\Http\Middleware\SetCacheHeaders::class,
        'can' => \Illuminate\Auth\Middleware\Authorize::class,
        'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
        'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
    ];
}