Menu disappears on mobile

Hi!

When I open the menu on mobile it extends below the bottom of the screen. When I try to scroll the menu disappears, making the bottom links unreachable. This only seem to happen on iPhones. I’ve tested both safari and firefox on two different iphones and both exhibit the issue. Android and chrome dev tools on a pc works fine. Link to website: https://goo.gl/LgQsTz.

//Mattias