Hello @Dave-uk,

Thanks for reporting this issue to the TP-Link Business community!

Could you please tell your controller version, your previous and current controller firmware with the build number?

Dave-uk wrote

When someone logs in to the controller from cloud access I'm getting the email alert as before but it says: "Cloud Access logged in to the controller from unknown Value".  Rather than the public IP address. 

Do you know which exactly device is trying to log into the controller from cloud website?

If you know it, please confirm whether this device showed the IP address in the email alert when it had the same behavior before you upgraded the controller firmware.

Please share a screenshot of the alerts.