Bootstrap 3 Dropdown Slidedown Strange Behavior when Navbar Collapsed

Question

So I was adding some animations to the navbar dropdowns, but for some reason the most accepted answer (Adding a slide effect to bootstrap dropdown) seems to break or become

Answer 1

$(document).ready(function(){
    $(".class-name").click(function(){
        $(".class-name").slideToggle(1000);//hear you can change value of slidetoggle i.e "slow","fast", or any number
    });
});