Below is the reason why your customer has applied the same coupon multiple times.
– If the customer has applied the coupon code as well as our app discount then it will not check the condition of the discount coupon code created from the Shopify Discount option and then the customer can apply the coupon for more than one order.
– If the customer has applied the coupon code but has not applied any of the discounts of our app then it will not allow using the coupon code more than one time because the condition of that discount will be checked.
For ex: If you have placed a total of 5 orders and use that coupon code in all 5 orders but from that 4 orders have our app discount + Shopify discount coupon code and 1 order only have the Shopify coupon code then again if you came to place one more order using our app discount then still you can use the Shopify coupon code but if you came to order with only Shopify discount code, not our app discount then you can not use that coupon code to place the order because you have already placed one order with that coupon code without our app discount and in this whole process the Order type does not matter.