Laravel built-in multilang not working correctly

thanks for taking the time to read this
I'm using Laravel 10.7.1
I have the languages folders setup correctly (I hope) in Resources/lang/ - ar/fr/en / messages.php

Here's the code in app.php

'locale' => env('APP_LOCALE', 'en'),
'fallback_locale' => env('APP_FALLBACK_LOCALE', 'en'),

Here's the route in web.php

use App\Http\Controllers\LocaleController;  
Route::get('set-locale/{locale}', [LocaleController::class, 'setLocale'])->name('locale.set');

Here's my LocaleController

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use Illuminate\Support\Facades\App;


class LocaleController extends Controller
{
    public function setLocale($locale)
    {
        session()->put('locale', $locale);
        App::setLocale($locale);
        return redirect()->back();
    }
}

Using these buttons to change the language

    <a href="{{ route('locale.set', 'en') }}">English</a>
    <a href="{{ route('locale.set', 'fr') }}">Français</a>
    <a href="{{ route('locale.set', 'ar') }}">العربية</a>

when I try this code to see what's going on

<div>Current locale: {{ session()->get('locale') }}</div>
<h1>{{ trans('messages.welcome') }}</h1>

The result is :

Current locale: fr
Welcome

Despite the message being correctly translated.

The signature for the trans helper is the following:

function trans($key = null, $replace = [], $locale = null)

You could pass the locale as the third parameter.

<div>Current locale: {{ session()->get('locale') }}</div>
<h1>{{ trans('messages.welcome', [], session()->get('locale')) }}</h1>

There is another helper that is an alias to trans. __.

<div>Current locale: {{ session()->get('locale') }}</div>
<h1>{{ __('messages.welcome', [], session()->get('locale')) }}</h1>