是否尝试添加计数回调？

// Register Custom Taxonomy
function custom_taxonomy() {
    $labels = array(
        \'name\'                       => _x( \'Taxonomies\', \'Taxonomy General Name\', \'text_domain\' ),
        \'singular_name\'              => _x( \'Taxonomy\', \'Taxonomy Singular Name\', \'text_domain\' ),
        \'menu_name\'                  => __( \'Taxonomy\', \'text_domain\' ),
        \'all_items\'                  => __( \'All Items\', \'text_domain\' ),
        \'parent_item\'                => __( \'Parent Item\', \'text_domain\' ),
        \'parent_item_colon\'          => __( \'Parent Item:\', \'text_domain\' ),
        \'new_item_name\'              => __( \'New Item Name\', \'text_domain\' ),
        \'add_new_item\'               => __( \'Add New Item\', \'text_domain\' ),
        \'edit_item\'                  => __( \'Edit Item\', \'text_domain\' ),
        \'update_item\'                => __( \'Update Item\', \'text_domain\' ),
        \'separate_items_with_commas\' => __( \'Separate items with commas\', \'text_domain\' ),
        \'search_items\'               => __( \'Search Items\', \'text_domain\' ),
        \'add_or_remove_items\'        => __( \'Add or remove items\', \'text_domain\' ),
        \'choose_from_most_used\'      => __( \'Choose from the most used items\', \'text_domain\' ),
        \'not_found\'                  => __( \'Not Found\', \'text_domain\' ),
    );
    $args = array(
        \'labels\'                     => $labels,
        \'hierarchical\'               => false,
        \'public\'                     => true,
        \'show_ui\'                    => true,
        \'show_admin_column\'          => true,
        \'show_in_nav_menus\'          => true,
        \'show_tagcloud\'              => true,
        \'update_count_callback\'      => \'_update_generic_term_count\',
    );
    register_taxonomy( \'taxonomy\', array( \'post\' ), $args );
}