Problems with variables products

Hi,
We are having a problem with the references associated with variables on the site.

In this example, candle number 1 is out of stock in the moloni and on the website let me buy 2 units, this article has an associated and well-associated reference.

As a rule, we think it is happening in articles considered as Father articles, but there should be no justification for this since it has an associated reference, as you can see in the example.

If you need to access the website backoffice, I send the accesses.

This is the page of example

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