On which page can I see this, can you please link me to that? The /shop/ gives me an error message.
My guess is, that the fixed position might be the issue here. Some mobile devices does not like fixed positions at all, and usually the solution is to set an absolute position, and move the element before the closing body tag. That is however not same as the fixed position, and it may not work as expected.Best,
If you like my products, don't forget to rate them on codecanyon :)