Winlink Express - cannot "Update MESH Nodes"

I've got a DtD'd 2-node network I am testing.  It connects to our main mesh network.  On the far-end (8 feet away and over RF)  I have a Windows 7 laptop connected to the node device.  Everything mesh and network-wise seems good.  The problem is when I run  Winlink Express (v1.5.11.0) and try to set up a new Telnet Post Office server.  Here is what happens:

• I select Add server - okay.

• In the next dialog I select Update AREDN MESH Node List - okay.

• When I select Update MESH Nodes I get a dialog that says it is unable to get info from master node localnode.local.mesh.  And it says the computer must be connected to a ARDEN MESH running firmware version 3.17.1.ORC1 or later.

• All my nodes are running Nightly 176.

• Also when I select View JSON List, all the nodes come up including the POST OFFICE node.

Finally, when I try this on my main PC (desktop) which also has Internet connectivity, it all works nicely and brings up a dialog saying that an advertised MESH service for Winlink post office was found.  Also the JSON data for the post office node looks the same for the desktop PC as well as the "remote" laptop.

When I manually set up the post office server on the laptop it all works so this problem is not a killer.  I don't know if the issue is with AREDN FW, RMS Winlink or something with my network or configuration.

Does anyone have any ideas?

Thanks, Mike ab4yy