The coupons arnae workin' cap'n

So in Paypal sandbox mode I have everything functioning in Events+ except coupons. On the recurring event I have given each of my four membership levels a separate discount. Once logged in on a test account on any one of those levels, I book an event. The discount for the level isn’t applied either before I click the Paypal Subscribe button or on the Paypal Test store page. What is it I am missing?