Good afternoon. The site has a payment processing system from Monobank.
The payment logic on the site is as follows: The client places an order - is redirected to the payment page at Monobank - Upon successful payment, it automatically redirects to the site's page (Thank You for Your Purchase page).
However, in about 40-60% of cases during payment, either the server or an error in the site's script causes it to recheck the payment, and even when a person has successfully paid, it redirects to a page stating that the payment was unsuccessful.
In the admin panel, I can also see that the payment was successful from the client.
Screenshot 1 - successful payment (server logs) Link to photo 1
Screenshot 2 - payment successful, but the client is redirected to the Fail page Link to photo 2
It is necessary to fix this chain so that it checks correctly. The site is written on OpenCart.
Also, as one of the reasons, it was mentioned that when creating the site, the person used a cracked widget for Monobank payment for OpenCart. This could be one of the reasons. If it turns out to be the case, I will purchase this widget on my side, and you will need to replace it.