Anybody else who have seen this issue?
We get alert that we have "NetFlow data stream from an unmanaged device".
Our AT&T router have more than one ip number and we pool the WAN interface of the router, but the netflow is coming from the localhost ip number.
This was fixed in some previous version but is now back in version 12.x
This may not be it since it was working correctly at one time, but I would verify that the "Netflow source" is configured properly within the Netflow configuration on your AT&T Router.