We have created a payment provider for GlobalPayments using their HPP method. For Umbraco 13.
Generally it works fine and payments happen and Commerce gets notified and the order gets finalised, etc.
However, every now and then we have an issue where the payment goes through fine in Global Payments but the user then sees a completely blank page at what looks like the Commerce callback URL. The Cart stays as a Cart (doesn’t get finalised) and of course, the orderfinalised hotification is not sent.
So we end up with payment taken but no order, etc. (we post data to a 3rd party site too).
We have logging that shows the payment page being loaded but then nothing. No more of our logs, no errors, nothing.
What could cause Commerce to not respond / accept / process a calback URL and leave you on a blank page? This is only occasional and generally it works fine. When I say occasional, it is something like 8 per day.
We have another website that uses GlobalPayments but not Commerce (or Vendr) and that does not have this issue (of course, I guess - but it also does not have any particular problems with the payment process)