Domain is located by a broadcast so if it's not showing up, either the other running hubs are prohibited from receiving that broadcase or the hub you are operating on is unable to receive the result.
I'd suggest starting with temporarily disabling the firewall(s) (if any) on one running hub and the one you are setting up to see if that helps.
You say "same network" but it's possible that there's a network device between the new hubs and others that might also be filtering this broadcast message.
Otherwise, don't worry about it automatically finding it and just supply the value manually.