Navigation Menu on mobile device – anchor links not working

Hello guys,

i have a little problem on the mentioned site and can′t find a solution on my own. Problem: When i visit the site with a mobile phone and expand the menu, everything looks good. But it looks like the whole menu is “one link” and not a collection of specific ones. I cant “click” a dedicated link. This is the reason why my anchor-links won′t work.

Any advice is appreciated.

thanks!

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