Exclude post types from restriction

Hi there,

I want to exclude some post types from access restriction without to go into any single post to set this up (sorry, not possible for more than 2000 posts).

I tried this:

add_filter( 'um_custom_restriction', 'exclude_custom_post_types_from_um_restriction', 10, 2 );

function exclude_custom_post_types_from_um_restriction( $custom_restriction, $restriction ) {
	if ( is_singular() ) {
		$post_type = get_post_type();

		$excluded_post_types = array( 'glossary', 'snippet', 'index_tag' );

		if ( in_array( $post_type, $excluded_post_types, true ) ) {
			return false; // keine UM-Beschränkung
		}
	}

	return $custom_restriction;
}

But this isn`t working. Any other ideas?