@thaikolja By default the plugin doesn’t alter the default Gutenberg behavior for custom post types. The plugin provides a ‘post_type_supports_convert_to_blocks’ filter hook that you can use to extend support to your CPT.
add_filter( 'post_type_supports_convert_to_blocks', function( $supports, $post_type ) {
if ( $post_type === 'my-cpt' ) {
return true;
}
return $supports;
}, 10, 2 );
Can you try the above code and let us know if that helps? Thanks.