Preview inside Gutenberg is broken ?

Hello,

The preview inside the editor doesn't work but if I save the page or the post, I have the correct display on the front-end.

    $meta_boxes[] = [
      'title'      => 'Hero',
      'id'         => 'my-hero',
      'description' => 'Un bloc pour mettre en avant un contenu',
      'type'            => 'block',
      'icon'            => 'awards',
      'category'        => 'layout',
      'context'         => 'side',
      'render_callback' => function () {
        echo '<header>Hello</header>';
      },
      'fields'     => [
        [
          'name' => 'Title',
          'id'   => 'title',
          'type' => 'text',
        ],
      ],
    ];

On Gutenberg

On website

Console

I missed something ?

Tested without any others plugins on twentytwentyfour theme

Metabox: 5.10.5
Metabox AIO: 1.31.1