function filter_product_tax( $query ){
  if( $query->is_tax('product-category')):
  		$query_object = get_queried_object();
  		$slug = $query_object->slug;
      $query->set('orderby', 'meta_value_num title');
      $query->set('order', 'ASC');
      $query->set('posts_per_page', 24);
      $query->set('meta_key', '_reorder_term_product-category_' . $slug . '');
      return;
  endif;
}

add_action('pre_get_posts', 'filter_product_tax');