jQuery scroll to top stopped working

I know my jQuery is working (my console.log statement prints) and I even got this code to run earlier. I disconnected from the internet and poof the jQuery scroll to top feature doesnt work. Here is the code

$(document).ready(function(){
    $('#back_to_top').on('click', function(){
        $('html, body').animate({scrollTop:0}, 'slow');
        window.scrollTo(0, 0);
        console.log('back to top tab clicked');
    });
});

But the page doesnt animate when I click the tab, given either method in the code block.

Thoughts?

EDIT

this block of code was preventing it from working, not sure why...

html,body{
    width: 100%;
    height: 100%;
    margin: 0px;
    padding: 0px;
    overflow-x: hidden; 
 }