Laravel session flash data always null

I can't flash data to the Laravel session. In my view, data is always null. I am using Laravel 5.8.35. I tried this solution but it changed nothing.

In my controller :

public function addMembers(AddMembersRequest $request)
{
    // Here I am just creating users using Eloquent

    // Then I redirect the user
    return redirect('/administration/users')->with('status', 'Members successfully created.');
}

In my view :

@if(session('status'))
    <div class="alert alert-success alert-dismissible fade show" role="alert">
        .
        <button type="button" class="close" data-dismiss="alert" aria-label="Close">
            <span aria-hidden="true">&times;</span>
        </button>
    </div>
@endif

Except if I am missing something, this is the same as the doc.
I tried with session()->flash('status', 'Members successfully created.'); but it changed nothing.

I read that could be a middleware problem so here are my routes and my Kernel:
Routes:

Route::group(['namespace' => 'Pages'], function () {
    Route::get('/administration/users', 'AdminController@showUsers')->name('user_list');
    Route::post('/administration/add-members', 'AdminController@addMembers');
});

Kernel:

class Kernel extends HttpKernel
{
protected $middleware = [
    \App\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,
    \Illuminate\Session\Middleware\StartSession::class,
    \Illuminate\View\Middleware\ShareErrorsFromSession::class,
];

protected $middlewareGroups = [
    'web' => [
        \App\Http\Middleware\Locale::class,
        \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',
    ],
];

protected $routeMiddleware = [
    'auth' => \App\Http\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,
    'signed' => \Illuminate\Routing\Middleware\ValidateSignature::class,
    'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
    'verified' => \Illuminate\Auth\Middleware\EnsureEmailIsVerified::class,
];

protected $middlewarePriority = [
    \Illuminate\Session\Middleware\StartSession::class,
    \Illuminate\View\Middleware\ShareErrorsFromSession::class,
    \Illuminate\Routing\Middleware\ThrottleRequests::class,
    \App\Http\Middleware\Authenticate::class,
    \Illuminate\Session\Middleware\AuthenticateSession::class,
    \Illuminate\Routing\Middleware\SubstituteBindings::class,
    \Illuminate\Auth\Middleware\Authorize::class,
];
}

via Chebli Mohamed