Products variants are not showing

Hello, we have a online shop sellling oil lubricants.

We have decided to upgrade Hikashop. We have Joomla 2.5.28. The websiote was developed some years ago.

We want to sell products only to registered users, however, public users can still view the products but of course not be able to add items to the cart.

The specific problem we are encountering is that when we go inside one product there is no dropdown options for it.

we have the following charatteristics:
1 lt
5 lt
25 lt
60 lt
250 lt

For the product prorace-industry.com/it/prorace/automobi...-auto-10w40-100-synt we added two variants, as you can see from the screenshot, but in the page itself is not shown.

why?

thanks
Davide and Lorenzo

Hello, I have sent you the data to view it. Thanks.

Hello Nicholas,

not sure why but the add to cart button is not showing. Please login into the site and check this product; prorace-industry.com/it/prorace/automobi...auto-10w40-tech-synt

as you can see we added two charateristics and their codes and prices. However the button is not displaying.

I found out the problem was the quantity.