What is the name of the domain?
What is the issue you’re encountering
PayPal Instant Payment Notification (IPN) is not reaching our Flask-based endpoint hosted behind a Cloudflare Tunnel (Argo). PayPal shows multiple delivery attempts, but nothing reaches our server. No POST logs appear, and the IPN confirmation flow fails. Manually testing the endpoint via curl -X POST https://deinxkleinanzeigen.de/ipn works as expected and returns 200 OK. TLS is valid and confirmed (Disable TLS 1.3) . However, PayPal’s real IPN seems to be blocked or rejected.
What steps have you taken to resolve the issue?
Verified the /ipn endpoint responds with 200 OK to test POST requests
Confirmed TLS certificate and domain setup
Tested IPN locally – works
Confirmed that PayPal’s notify_url is correctly set
Checked Tunnel config with proper ingress forwarding
Disabled TLS 1.3 temporarily
No custom WAF or Access rules defined
What are the steps to reproduce the issue?
Create a PayPal payment with notify_url=https://deinxkleinanzeigen.de/ipn
Complete the payment and trigger payment.execute()
PayPal attempts to send IPN to /ipn
Cloudflare returns HTTP 530
IPN never reaches server
No database update or confirmation occurs