why purchases do not appear in product's subpanel ?

Hello,

In the product’s subpanel called “purchases” I have noticed that no data appears, even if the product has been sold many times ( = invoices ).
I would have expected to see the list of invoices related to this product.

Could anyone explain why ? Do I need to change some settings, add a relationship ?

Thank you for your help.

Hello, Anyone having the same issue ?