In fact, the difference is in the [] in the produit_id1 because there is only one message so the work considers this is not a list and not add the hook.
In the second example there is no problem, there many message for a product if I am an aggregate and work considers a list.
So my problem is how to add the hook [] in each product.
This is an international forum and English is the language we use. Posting in English will allow you to get more visibility and more help. Thanks for your understanding!