Coupon not working

Hello,

I do not have an option to change the setting for coupons generated via prize wheel to accept all emails.
I spinned the wheel using email adress “mirkosm6@gmail.com” and i received the coupon TNDBOF on my email adress. When i entered the coupon on the checkout page and used my email adress “mirkosm6@gmail.com” i got the same notification again: please enter a valid e-mail adress. When i go to coupons and check the allowed e-mail adresses tab i see that my email adress mirkosm6@gmail.com is in there, but the coupon code still does not work.