Drop Down Navigation not working on mobile

My site is having an issue where after touching the screen on a mobile device (phone or vertical/portrait view on a tablet), the main drop-down navigation is taking up the left side of the screen/preventing other page content besides the main header from displaying. The latest WordPress version and all plug-ins are up to date (plug-ins were all deactivated/tested and are not causing the issue.) And Desktop version looks great. Any help you can provide in sharpshooting this issue would be appreciated.

The page I need help with: [log in to see the link]