multi variant bug?

[geraldkoo]

Hi All

I have this problem with the multi variant custom field , please refer to the video
https://www.youtube.com/watch?v=stMOkDOexbM

small has 1 item
medium has 0 item
the product  does not change to "notify me" when click on small item again.
Seems like the URL points to small / medium instead of the other alias url
Anyone knows a solution to this?

Product link http://alessialove.com/new/index.php/shop/clothing/dresses/rhea-tuck-dress-detail

your help much appreciated