Problem with attribute stock

Hello,
On my website I have products that can be bought in variation.
On the different products I always have 6 of stock and each product has 3 variation: 1 person, 2 people and 5 people.
6 of stock means 6 people, so we can buy 6 quantities of person, 3 quantities of 2 people, etc …

So I have a “Person” attribute where I have not defined the “Manage Stock”.
I created an “Attribute Stock” by defining for my attribute “Person”, the stock multiplier for each value: 1 person = 1 stock, 2 people = 2 stock, etc..

And finally I created a product with 6 stock, with the attribute “Person” and the 3 variations that correspond to the number of people.

But I don’t understand, the stock of the attributes is not taken into account on my product and I can add 6 of quantity of my attribute which has a multiplier of 2…

I don’t know what I missed …

Thanks to you!