Page content disappearing when menu slides out

(page login is “123”)

Hey,

I implemented shiftnav on this page and got everything working just fine. I just registered a problem that when i dismiss the menu, it slides out fine but the page content disappears – only the background-color is visible – until the menu is off canvas again. The problem occurs both mobile and desktop both Chrome.
On Safari, the content is hidden all the time and only shows when the menu is toggled.

Is this some setting I have to apply, did I mess up something?
I tested the menu on shiftnav.io to see if its a general problem, but there the content does not disappear.

Help is appreceated.

• This topic was modified 4 years, 10 months ago by rsdkd.

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