Essentially - I update the URL in the Current settings Notification URL with a new URL  -and PAyPAl continues to send to the old URL -
even though it clearly shows the new URL as saved and updated Message delivery Enabled.

I had set a URL as my 'Notification URL' - https://example.com/ppl-name1.php - in my PayPal sandbox account. It worked fine and testing went well. I decided to rename my 'Notification URL' to https://example.com/ppl-name2.php.

I updated the detail with the new URL here: https://www.sandbox.paypal.com/cgi-bin/customerprofileweb?cmd=_profile-ipn-notify

It accepted and saved the new URL.

But now paypal still sends the notifications to the old URL. No matter how many times I try - even deleting the saved URL setting and turning off notifications and turning them back on.

It still will not send to the new URL. Yet it clearly shows the new URL as the saved value.

I have verified the old URL is being called in the IPN History page.