Auto return for website payments stopped working

[david-b]

The auto return on website payments stopped working. It has been successful for years.

The profile website payment preferences are unchanged. Auto return is still on. URL is correct.

Identity token for payment data transfer is correct.

The web server's log file doesn't show the return file as being opened in nine days.

We have several successful payments in those nine days.

Any such thing as an error log for the Paypal side?

Any idea on what else to look for?

Thanks