Why is the discount code usage count not increasing in my app?

Hi!

I’m develop an Shopify App.

It creating discount codes for customers.

It’s been working fine until now, but I received an inquiry from a shop the other day saying that “I Can use the discount code and still use it again".

When I checked, the discount code usage_count, which should have been used, was not increased. Also, I checked the store’s admin screen and it was “0used” but the report seemed to have been generated.

Why is this?

Thank you!

The client informed me that I am now getting a “discount code has been used” error.
However, the usage_count has not increased.

Best regards.