Unable to configure from different subnet

I place all of my IOT devices on a different subnet from my home devices. The home LAN can reach all devices on the IOT LAN, but not the other way around. This works well for everything except Sonos and apparently Konnected.
When I moved the Konnected panel to the home LAN, I was able to configure it from Homebridge but couldn't when Konnected Pro was on the IOT LAN. I even tried to add a firewall rule allowing all traffic from Konnected to the Homebridge server, but that didn't resolve it. 
Is this by design?

Tracking this in a ticket separately. Will circle back with any relevant knowledge for the public on this issue.

I am also trying to do the same with no luck. Has there been any updates to this?