Hi rick,
So this usually comes down to a hub configuration / communication issue.
When hubs are in different Vlan or network they are usually connected via a tunnel.
This allows all additional traffic to be routed over the tunnel port 48003 by default.
If there is no tunnel set up then the application is expecting that all communication will be direct IE discovery_agent can talk directly to the discovery_Server on the primary on the port for the discovery_server.
I would suggest that if you have not to setup a tunnel between the two hubs per the hub documentation.
then to make sure you can not communicate on ports 48000-48002 in iether direction between the two hubs.
If you have both direct and tunnel setup you will get unexpected results.
once this is done I would test again.
Also you can check your hub loglevel 3 logs for communication errors.
one last thing I would make sure all hubs are on the same version.
Below are recommended version best first
7.80HF9 CA Unified Infrastructure Management Hotfix Index - CA Technologies
7.72
7.63
hope this helps.