Coupon code commissions not assigning

I have purchased 5 licences for affiliate pro for wordpress. I have an paid Ecwid account and it all is working well for general affiliate commissions etc. I set up coupon codes and all is working OK with Ecwid. I have done everything by the documentation and excellent videos but I can not get the commission through to the affiliate with the coupon code. I have tested a number of ways, gone through new user registrations as per doc. around 10 times.