Variations of a product doesn’t works properly

Hello
You can see the problem for this product (for example): https://aopticadeana.com/producto/ray-ban-3183/
This is a product with 2 variations. One of them is in stock (grafito + verde polarizado), so I want to apply a discount. The other one (grafito + espejo plata) is not in stock, so I don’t want the discount to be applied but it do it.

I attach the screenshot corresponding to the the list settings and the evaluated products (https://prnt.sc/oqh70c and https://prnt.sc/oqh7a1)
Also, I attach the screen capture where you can see the stock status that I mean (https://prnt.sc/oqh6nb)

It seems as the general product (Rayban 3183) is in the list, it makes the discount applies to all the variations…
So also I’ve tried adding any other meta key to remove the general product (Rayban 3183) from evaluated list, but in that case the offer doesn’t appear in the product page but it does in the cart page.

Hope you can help.

Thanks in advance

The page I need help with: [log in to see the link]