Not having looked at it yet I took a dive into it today. I go the same results you did. So after doing some digging around it looks like one has to have at least L2 switches with things like SNMP discovery enabled, etc. Do you have that? I don't but will try spinning up a switch to see what happens. When I was searching for "links not being auto created" there were many who commented that they did not turn on auto links and just manually created them.
One nice thing about this is that, if you are on a managed network, you can just spin up a RouterOS instance, put it in bridge mode and then use it as a discovery and monitoring appliance.
Edit: found
this post which has info on setting up on a Ubiquiti switch and The Dude. I'll give it a try in a while.