Can't render dateTime - twig

Question

I make an entity "comment" with fields id, pseudo, email, comment and published_at.
My entity :
/**
* #ORM\Column(type="datetime")
*/
private $published_at;
public function __construct()
{
$this->published_at= new \DateTime();
}
public function getPublishedAt(): ?\DateTimeInterface
{
return $this->published_at;
}
public function setPublishedAt(\DateTime $published_at): self
{
$this->published_at = $published_at;
return $this;
}
My migration:
public function up(Schema $schema) : void
{
// this up() migration is auto-generated, please modify it to your needs
$this->addSql('CREATE TABLE comment (id INT AUTO_INCREMENT NOT NULL, pseudo VARCHAR(25) NOT NULL, email VARCHAR(255) NOT NULL, comment LONGTEXT NOT NULL, published_at DATETIME NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB');
}
I make a controller :
$comments = $commentRepo->findBy([], ['published_at' => 'desc']);
// dd($comments);
return $this->render('comment/comments.html.twig', [
'commentForm' => $form->createView(),
'comments' => $comments,
]);
My render twig :
<div>
{% for comment in comments %}
<div class="text-light">
{{ comment.pseudo }}
{{ comment.published_at|date('d/m/Y H:i:s')}}
{{ comment.comment | raw }}
</div>
{% endfor %}
</div>
For {{comment.pseudo}} and {{comment.comment}} display well
But for {{comment.published_at}} I have this error :
Neither the property "published_at" nor one of the methods "published_at()", "getpublished_at()"/"ispublished_at()"/"haspublished_at()" or "__call()" exist and have public access in class "App\Entity\Comment".