We are working on a project which has PayPal integration. We have created the necessary buttons for payment and created the IPN notification URL. We have published the project and everything worked fine. For some reason, we need to modify the current IPN URL to a new one. So we changed it and updated it on the PayPal account also. But for some old users, it still called the Old IPN URL after payment. These users are using a recurring payment option. So PayPal automatically calling IPN for each interval. How to solve this issue.