Coupons not showing up in the Membership plugin backend, but do actually work!

Hi Guys, loving the coupon code feature for Membership, however when I create a new coupon, although it does actually work in the payment gateway, it's not showing up in the list of coupons in the backend. Therefore I can't edit or delete any coupons.

I have just done a Membership>Options>Advanced>Membership Tables Repair, but still nothing. Tried adding a new coupon after doing the repair too.

Please help

Ali