"Add to cart" button in category list works only if defalut combination is available

[skiracecenter]

I have problem:

"Add to cart" button works just in case defalut comboination is in stock.

When defalut combination is out of stock in category list You could see "view" button.

Example 1

Product X with given combinations:

• A combination (defalut combination) - 0 products available
• B combination - 2 products available
• C combination - 3 products available
• D combination - 4 products available

In this case there's no "add to cart" button in list of category products

Product X with given combinations:

• A combination (defalut combination) - 1 products available
• B combination - 0 products available
• C combination - 0 products available
• D combination - 0 products available

In this case You can see "add to cart" button under product picture on category page

 

Example:

https://skiracecenter.pl/36-narty-damskie

"DODAJ" means add to cart

"WIĘCEJ" mean view more