Menus not activating on some mobile devices

Hi,
I am new to building websites and have no coding experience so have been relying mainly on plugins.
I am running the catchbox theme on my website. The address is http://www.blindsightseer.com
I have noticed that on IPhones the mobile menu buttons display but do not activate when selected. I have not edited any code I have just installed some plugins. I have made sure turn on mobile menus is activated within the theme options. I have also turned on the jetpack optimisations for mobile devices. I have had the jetpack setting for mobile devices on and off and it makes no difference. I sought advice from my website host but they told me my website was not compatible with mobile devices and suggested I purchase a service to sort this out. I have also run the google tester which identified my website was compatible with mobile devices.
Some advice would be greatly appreciated so I can work out what is wrong.