Costprice not added

Using my Dolibarr
1

Dear All,

I am using 10.0.2. and tried to use the product variants for a product which has different colors and different prices on colors for sale and purchase
and the product is a set of 2 pieces,

  1. base product --> product
  2. cover with different color --> variant

At the variant it self it is possible to add the extraprice (sales price) but it is not possible to add the costprice.
The costprice is not taken from the Variant itself

E.g.
Base Produkt: Salesprice=10,- Costprice=5,-
Product Variant: +4,- Costprice=+2,-

The Salesprice in the proposal (order or invoice) is added correctly, so it equals to 14,- but the costprice is not added.
This behaviour causes a wrong margin calculation.

Is there a setting to activate this feature or has somebody an idea to fix this?

All the best,
Arnold