Hi Jerome,
That is a wonderfully complete answer, thank you so much! My partner was going to look into this, but he has had no time, which is the reason for my delay in answering here. Just now I was looking at it again with my son/webmaster, and everything seems to be working well! I cannot explain it, I previously thought I myself had tried all possible combinations of settings in products and coupons, but obviously not. My apologies.
You have as always been a tremendous help for us.
Kind regards,
Marjoline