Roy,
I have a suggestion that might help. By default, we configure the Worker to use a broadcast to "autodiscover" the Supervisor. Since you are operating two domains, this might be somehow confusing the Supervisor and preventing it from responding to Workers in both domains simultaneously. If you configure your Workers to point directly to your Supervisor, rather than autodiscover, they might work better.
You can use the Configuration GUI to reconfigure the Workers. Just add your Supervisor to the Supervisor field, and clear the Domain field (that turns off the autodiscover). Alternatively can edit their qb.conf file, by editing these entries:
qb_supervisor = mysupervisor
# qb_domain =
Commenting out the qb_domain should be sufficient.