sticky element is flickering with mouse scroll not with scrollbar

Hi in this page

https://neos.anekitalia.com/olympic-champion

you can notice a yellow bar that becomes sticky with this simple code

<!--per menu fixed-->
<script>
jQuery(document).ready(function($){
    $("#sticky-flotta").sticky({
      topSpacing:-2,
      zIndex:9999
    });
  });
</script>

this is working as expected but if you scroll fast with your mouse scroller, the element is flickering for an instant with CHROME FIREFOX and IE, this doesn't happens if I use the scrollbar with my mouse pointer. any suggestion to fix this? many thanks

garand / sticky

sticky element is flickering with mouse scroll not with scrollbar #286