I am trying to use pop-up layers to create a menu on my website. This is working fine on all devices I've tested. However, as soon as I add variants to the site, the links on the pop-up layer stop working in Safari on iOS devices (with both iOS 10 and iOS 11).

Here are two examples:
No variants - works fine in Safari on iOS: www.wood-net.co.uk/xwd/sela/menu
2 variants - links don't work in Safari on iOS: www.wood-net.co.uk/xwd/sela/menu/break

Does anyone have any suggestions for how I can fix this, or what the issue might be?