Sticky sidebars

Hi

I'm trying to make the last widget in my sidebar sticky using the code discussed here.

@media(min-width: 769px) {
    .inside-right-sidebar, .inside-left-sidebar {
        height:100%;
    }

    .inside-right-sidebar .widget:last-of-type, .inside-left-sidebar .widget:last-of-type {
        position: sticky;
        top: 60px;
    }
}

I've disabled all plugins and cleared all cache, still not working.

Any ideas?