How do you get field groups to render for a block_content entity loaded programmatically? I added some field groups to my display, but they don't render on my custom block_content entity.

$blocks = \Drupal::entityManager()-&gt;getStorage('block_content')-&gt;loadByProperties(['type' =&gt; 'footer_bottom']);
if (!empty($blocks)) {
  $block = array_shift($blocks);
  $render_controller = \Drupal::entityManager()-&gt;getViewBuilder('block_content');
  $footer_bottom = $render_controller-&gt;view($block);

  return $footer_bottom; // won't render field groups.

}


I see the field groups in the render array when I dump the $footer_bottom array:

  "#fieldgroups" =&gt; array:2 [▼
    "group_tricolumn" =&gt; {#5505 ▶}
    "group_subfooter" =&gt; {#5465 ▶}
  ]


Is there another step to process the field groups?
The field_group module does not currently support the block entities, see Does not work with blocks [2689501]