Featured Image Option not showing up in Gutenberg Editor

Hello,

I want to add featured images to posts in the Gutenberg Editor, but the featured images section does not show up. In the Neve-Option I can reorder the elements, but there is no way to select a featured image. I use WP 5.7. and Neve 2.11.0 (with a child theme).

I even tried to add the post-thumbnail section in my functions.php, but it doesn’t work.
add_theme_support( 'post-thumbnails' );

Thanks for any help