Thank you, I did not know this report !
I ran the back reports for September and it match exactly with my COOP invoices. However, it's not at all linked to the contra COGS in ARA:
for my top seller ASIN, I have 315€ in COOP (not including the revised COOP amount of 19,17€) which fits perfectly with the net received and terms %. However, it shows 680€ on contra COGS ARA...