Steps to reproduce:

1. Make undiscoverable one item on host1, for example change interface name
2. Try to create graph on host2 with outgoing traffic from host2 and host1 (with undiscoverable interface)

Result:

After you press the Add button, you will see a blank screen.

Graphs section stops opening on host2.

New graph appears on host1 and becomes undiscoverable.

Expected:

Graph created on host1.

Everything works fine.