Using radio FormElement in a drupal 8 ListBuilder

I made a custom configuration entity, and I'm trying to set up radio buttons in the listBuilder. This is done in the core module language without any problems, but when I try to do the same trick with my custom entity I can't get any radio button. Instead the attributes are rendered in the html element.

    public function buildRow(EntityInterface $entity) {
      $row['label'] = $entity->label();
      $row['default'] = [
        '#type' => 'radio',
        '#parents' => ['site_default_language'],
        '#title' => t('Set @title as default', ['@title' => $entity->label()]),
        '#title_display' => 'invisible',
        '#return_value' => $entity->id(),
        '#id' => 'edit-site-default-language-' . $entity->id(),
      ];
      // Mark the right language as default in the form.
      if ($entity->id() == $this->languageManager->getDefaultLanguage()->getId()) {
        $row['default']['#default_value'] = $entity->id();
      }
      return $row + parent::buildRow($entity);
    }

Then I get this html element as a result without any errors in the logs:

<td #type="radio" #parents="active_scsp_server" 
#title="..." #title_display="invisible" 
#return_value="pre" #id="edit-active-scsp-server-pre" #default_value="pre">
</td>