i installed a plugin temporary ( Variation Swatches for WooCommerce
) this plugin work, but i wold like to use your system and delete this plugin, i have same bug with your system on 5 sites with xstore.
I saw that the videos I had attached previously were private, so you couldn’t see them… Sorry, now i enabled video of the bug to public view, see video on private area with error console, i are sure, that you are able to reproducing same issue on your demo site if you set 10 colors and 12 size with different quantity and setting 0 disponibility on two size.. Now you are able to click in the products not present in stock and does not see the X to the unavailable sizes.
You see error on private area.