Post is always empty on live server

Here is my code:

The HTML code:

Code:

<form method="post" class="table">
    <label for="email">Adresse email</label>
    <input type="email" name="email" id="email" value="{email}" autofocus>
    <div>{+validation_errors field=email+}</div>
    <label for="password">Mot de passe</label>
    <input type="password" name="password" id="password">
    <div>{+validation_errors field=password+}</div>
    <button class="full-width">Se connecter</button>
</form>

The controller (method User::login):

PHP Code:

    public function login()
    {
        var_dump($this->request->getPost()); // array(0) { }
        var_dump($_POST); // array(0) { }
        $login = $this->request->getPost();

        if ($this->request->getMethod() == 'post') {
            if ($this->validate('login')) {
                $this->auth->login($login);
                return redirect()->to('/');
            }
        }
        $this->useTables();
        $this->data['email'] = $login['email'] ?? '';
        $this->render();
    }