/one/two/three first causes the breadcrumbs to render in the order three / one / two, loading /one/two first causes the breadcrumbs to render two / one./users to /users/:userId is causing the breadcrumb to render multiple times - but only if the user's data hasn't already been loaded, so i think something weird with transitions is going on there. Haven't managed to reproduce this one yet. I did notice that even though the breadcrumb component was running 3 times, onCleanup was only firing once rather than twice