Why is PayPal sending failed payment notifications to the client later than Stripe or Authorize?

There is a difference in how PayPal API works with regards to failed payment notifications, when compared to Stripe and Authorize APIs.

In the case of Stripe and Authorize, the payments are initiated from the Coaches Console end and that is why notifications are sent after each failed attempt to charge the client. Meaning the Coaches Console system knows about the failed attempts more quickly.

In the case of PayPal, it is PayPal that initiates the payment attempts on their end, but does not inform the Coaches Console system of each failed attempt. After 3 such attempts over a number of days, PayPal finally declares the payment as failed and conveys this result to the Coaches Console system. That is when the Coaches Console can mark the payment as failed and send the notification to the client.