Hi there I’m using a namba child theme… 

Hi there, I’m using a namba child theme and every time I call the site from the mobile version the menu button won’t work the first time. I have to reload the page and then it’ll work. Vistiors obviously aren’t able to use the site.
I’ve tried to deactivate alle the plugins, but the problem remains :(
Any ideas anybody?!
http://wab-livemusic.de/