I am currently diagnosing a PayPal issue at the company I work at for a particular client. The company currently uses the deprecated method of building a redirect URL in order to process payments. When generating the PayPal redirect url for our customers, one of the parameters specified is the return URL (also known as the PDT, &return=...). After completing the paypal purchase, the user is redirected to our custom recipt page, which looks for the presence of a custom “cm” value in the query string, or a “custom” value in the formdata, which is specified when building the PayPal url. This custom value is our internal transaction guid (not PayPals "tx" value). For whatever reason, for a new client of ours, the standard query string parameters (cm, tx, amount, cc, etc...) are not being appended when redirecting to the return page, which is causing our recipt page to fail as we use the custom value typically found in the query string to find the transaction internally. I know the transaction is successful as I've examined the IPN log, and all went through as expected.
Log for client where the query string is present:
For the new client:
Question is, does the client need to change anything in their account to make this work? It is still working for our other clients, so I'm inclined to believe it is a configuration issue. Unfortunately the individual that wrote the PayPal integration here no longer works here, so I'm trying to work backwards.