So I was setting up an AirRouterHP, got AREDN loaded up just fine. I was messing around with getting it configured, and apparently got it into a "mesh access point" mode ( I can't remember the exact wording - but it's on the drop-down list under the basic setup window). The exact selection was listed as being deprecated in a future release, if that helps. Now it does function when I connect a node to the AirRouter - as it's supposed to I think.