Responsive Menu – remains over content

Hi,

I am using visual composer on the backend to create this site:

http://danishforcommissioner.com

Everything works great until you begin scrolling down the page… If you leave the mouse cursor over the top menu and scroll down about 500px or so (??) the menu remains in an “expanded” state and the vertical dividers between menu items extend down…

there is a screenshot of what I am experiencing here: http://s33.postimg.org/qbjyoyfen/Screen_Shot_2016_05_23_at_6_42_06_PM.png

can someone please explain what is happening and how to fix?

thanks and I appreciate you help!

Paul