Mobile menu not displaying

Greetings,

I am having an issue with the menu not displaying on the mobile. While using a child theme once you click on the menu it briefly displays- then disappears leaving the ‘X’ instead. I’ve contacted the author of the Salon plugin that I disabled to see the menu working.

Upon talking with them over the weekend, they have come back that it may be the javascript from the theme that is affecting the menu.

https://www.dropbox.com/s/i5jfuhkw4g6to94/Screenshot%202016-03-21%2015.15.52.png?dl=0

I’ve already tried making some of the suggested additions to the css file but nothing is working.

The website is https://hydeparkhairsalon.com

All help is appreciated.

Thanks
Tariq