Excessive webhook retries shown as 'Pending' in PayPal Developer Dashboard; repeated deliveries of same event over hours/days; potential event loss after 3 days if unresolved.[PayPal Docs](https://developer.paypal.com/api/rest/webhooks/)

Webhook listener returns non-2xx HTTP status (4xx/5xx), times out, or is unreachable, triggering PayPal's retry mechanism (up to 25 attempts over 3 days with exponential backoff). Developers often verify payload via API call synchronously, delaying/blocking the 2xx response.[Stack Overflow](https://stackoverflow.com/questions/65974110/what-needs-to-happen-for-paypal-webhooks-status-to-change-from-pending-to-succ)