Heya,
I just noticed a usability issue on the payment page (https://www.jimmyjoy.com/checkout/payment)
When you select Paypal as payment option, the usual Save and Continue button is hidden and replaced with the *Paypal Checkout * button. That means you can’t trivially apply a coupon code on that page.
It does work by entering the coupon code and pressing Enter, but that’s of course slightly suboptimal 
Regards,
Cunctor
.