The application is using standard IPN notification method and it was working fine. Recently, the application is migrated to new server and after migrated, the payment notification returning from paypal is triggering twice. There is no change in code. We just migrated the whole project and the database.
According to IIS log file, IPN notification is triggering again in 20 seconds for the same transaction.
May I know what is the possibility? How can I debug for this?
