Order with a product in more being added alone

[pieroso]

Hi, I use joomla virtuemart 3.6.4 and 3.0.18, multivendor configuration, it happens something new and strange in the cart it all seems ok, but in the order I find a product more that has not been added by the purchaser, the  amount of this product, however, is not added to the total amount of the order.In addition, the product that has been added is not for sale, I also looked in the database tables, but can not find it !!!!Is there anyone who can give me a hand?Thank you.Piero.

[pieroso]

I repeat the call.
Please anyone can help me?