Permlink sub category

Hi there,

I have this category for my products:

Bag in Box
-Accessori
-Capacità
-10 Litri
-20 Litri
-3 Litri
-5 Litri
-Serigrafia
-Anonima
-Calici al Tramonto

I created my first product.
It is in “5 litri” and in “calici al tramonto” and the slug is: domain/prodotto/bag-in-box/capacita/5-litri/nameproduct

then I duplicate it. It is in “10 litri” and in “calici al tramonto” but with the second one I had a problem:
The slug turned in: domain/prodotto/bag-in-box/serigrafia/calici-al-tramonto/nameproduct

I need the same slug in each product, I wasn’t able to manage it. I don’t undestand the reason why.
Could you help me? I need the first slug construction for all of my products.

Thank’s