Inventory is removing 2 items per sale, now what?

[studioalef]

Good morning people,

I have a problem with my prestashop stock. It turns out that even the customer buying only one product unit the prestahop removes two items from the inventory, is there any native configuration to solve this?

For example, if in stock I have 1 item, when the customer buys this item my stock ends up -1.

Or if I have 10 items and the customer buys only one item, my stock gets 8 items. The correct would be 9 items.

How can you?

[NemoPS]

Prestashop version?
Are you using packs?

[Scully]

I have read similar threads referring to late 1.6. versions. But only if the order is made or changed from the backoffice.