laravel 5 MethodNotAllowedHttpException error

Newbie to Laravel 5.4. Not sure where my error is. I created a logout button for signed-in users. My logout throws an error: MethodNotAllowedHttpException in RouteCollection.php line 251. I have a logout function in the Login Controller (Controller>Auth>LoginController.php) and a post route in web.php. What am I missing? Click here to see image of MethodNotAllowedHttpException full error message

Navbar

<div>
   @if(!Session::has('id'))
   <li> <a href="">Sign in |</a></li>                
   <li><a href="#"> Join </a></li>  

   @else
   <li><a href="">Sign Out</a></li>
   @endif
</div> 

Controllers>Auth>LoginController.php

<?php

namespace App\Http\Controllers\Auth;

use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\AuthenticatesUsers;

class LoginController extends Controller
{

/*
|--------------------------------------------------------------------------
| Login Controller
|--------------------------------------------------------------------------
|
| This controller handles authenticating users for the application and
| redirecting them to your home screen. The controller uses a trait
| to conveniently provide its functionality to your applications.
|
*/

use AuthenticatesUsers;

/**
 * Where to redirect users after login.
 *
 * @var string
 */
protected $redirectTo = '/profile';

/**
 * Create a new controller instance.
 *
 * @return void
 */
public function __construct()
{
    $this->middleware('guest')->except('logout');
}

public function logout(Request $request) {
    Auth::logout();
    return redirect('/home');
}
}

web.php

Route::group(['middleware' => ['web']], function () {
  Route::post('/signup', [
    'uses' => 'UserController@user_register',
    'as' => 'signup',
  ]);
  Route::get('/profile', [
    'uses' => 'UserController@getProfile',
    'as' => 'profile',
  ]);
  Route::post('/logout', [
    'uses' => 'LoginController@logout',
    'as' => 'logout',
  ]);
});


Auth::routes();

Route::get('/home', 'HomeController@index')->name('home');

via Chebli Mohamed