I have two users: A and B A: checkout with Paypal B: checkout with COD They apply coupon code: XXXXABC
In Admin Setting: Uses per Coupon: set to 1.
However, user A in Payment Review (Paypal Review) use B in Order Review. User A and B click Place Order at the same time (or late seconds). Both of them applied XXXXABC coupon code. But, Uses per Coupon: set to 1 in Admin. Expect result: Only one user can apply this coupon code.