It's working on your site, I clicked the sub-indicator of your
Services menu item and it toggles the sub-menu. At first glance, looks like there is no sub-indicator because of its color versus its background. So please also change your sub-indicator's color to white.
Or may I know what toggle behavior you're expecting? You can only have two possible link, anchor (where clicking the text will toggle it) and sub-indicator (where clicking the dropdown indicator like arrow will toggle it).