Mobile menu causes scroll extension beyond page

Hi all,

I’m experiencing problems with my mobile menu on the following site:

With the mobile menu open, the page scrolls far beyond the actual end of the page as per the design.

Also in the designer, the menu layout is completely messed up, which makes it difficult to edit (that’s a lesser issue though).

It seems to have something to do with the dropdown widget. Any help?

Here is my site Read-Only: