Does that help The cURL request initiates a HTTP POST back to PayPal in order to validate the IPN message. If it stops at this step, it means you do receive the IPN POST from PayPal, but you've got a problem connecting back to PayPal. What does // error_log("Got " . curl_error($ch) . " when processing IPN data"); contain?
Paypal IPN working in IPN simulator but fail in sandbox environment
PayPal Instant Update for Express Checkout stopped working [sandbox]
By : Jeff Alexander
Date : March 29 2020, 07:55 AM
this will help I spent like four weeks coding a plugin to work with PayPal Express Checkout instant update. It was working perfectly in the end with shipping and taxes updating as expected. , I have the same problem.. UPDATE..