Hello,
We have enabled the official WooCommerce theme Storefront, checked your site and faced the same issue https://gyazo.com/68897f6180cd01a5515f1df9177ed77f You told us that it worked for you with default theme but as you can see from the video it does not work for us. I suppose the problem is related to WPML plugin, so, contact WPML or WooCommerce support because we are able to help you only if the problem is related strictly to our theme.
Regards