[Wilfrank]

I made a small change so that the user can choose the sort order, but can anyone tell me why it does not work?

function custom_bbp_has_topics($order) {

  switch ($order) {
    case 1:
        $args['order'] = 'ASC';
        break;
    case 2:
        $args['order'] = 'DESC';
        break;
    default:
        $args['order'] = 'DESC';
  }
  
  return $args;
}
add_filter('bbp_before_has_topics_parse_args', 'custom_bbp_has_topics' );