Cart is completely broken on all Apple devices

[shaunsnaith]

We have an ongoing problem with our shopping cart.  We have had a Shopify Expert working on it for nearly two weeks now but hasn't been able to make any progress.

The problem we have is that any apple users can't add or subtract quantities on the product page, they have to input a number and hit return.  When you then get to the cart they can't adjust the quantity at all, the add and subtract numbers don't work work and even when you enter a new number in the quantity box nothing happens.  First time visitors might be able to add quantity using the add and subtract buttons on the product page but then as soon as you look at another product you get the problem of all the buttons not working again.

Is anyone else having the same issue, has anyone had it before?  Can anyone shed light on what the problem might be?  We have a back up from Sept last year which we think won't have the same problem.  We've optimised and changed the website a lot since then but should I just bite the bullet and restore an old version?

Half of our visitors are on apple devices and I know this will be hitting our CRO.

If you want to check out the problem for yourself our address is advancedacoustics-uk.com

Any help you can offer would be greatly appreciated.