Unable to select number of products

-- url of the page with the problem -- : www.paardenmestonderzoek.com/paard/verzo...t/394-dazenweg-spray
-- HikaShop version -- : 4.0.1
-- Joomla version -- : 3.9.2
-- Browser(s) name and version -- : Chrome71.0.3578.98

Hi there,

Today I noticed a strange issue with some products in my Hikashop. The problem occurs when the product has variants, eg; 250ml or 500ml
Now as soon as you open the product (*see link), of course the standard variant is selected. In this example it is the 500ml. If you do not change the variant, you can select the desired number of products through the dropdown menu. (Although I do see a strange placeholder appearing as well). If you change the variant to, for example, 50ml, you are unable to select the desired number of products, even though there is plenty of stock (in this example there are unlimited products available). If you change back to the standard variant, you can also no longer select the number of products for the standard variant. You can click all you want, it won't give a dropdown menu.

Thanks! I had figured that out indeed, but I thought there might be an issue why the "use chosen library" setting didn't work. I changed it to another setting and I have no issues now.