Mega Menu on Mobile

So, I am having some problems with your menu on mobile. A couple of my parent menu items have a significant number of sub-items, hence the use of a mega menu in the first place. However, on mobile, the sub-menu drops down but I can only see a small portion of the sub-menu and I cannot scroll to see the rest. So then I thought to hide the sub-menu on mobile but that doers not seem to work.

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