The conclusion I make from that is
There is nothing wrong with this SD card nor with the Pi-Star hardware.
The problem is downstream from that -- eg: either your "caravan" router/extender is blocking traffic on needed ports, OR whatever router that talks to is blocking that traffic.
Make sure your "caravan" router forwards the ports shown {Note: some Google hits seem to imply this is only needed for particular reflector types viewtopic.php?t=1063&start=10#p5821 }
https://www.k6jm.com/portforwarding.htm
https://github.com/dl5di/OpenDV/wiki/Fi ... Forwarding
(note: Pi-Star somehow negotiates those with uPnP capable routers, as I recall, which is likely why "Home" is working; it may also be negotiating with the "Caravan" router/extender in which case the problem is whatever WiFi router it connects to -- you'll have to be able to configure THAT node manually as I doubt the extender relays uPnP information [or the end WiFi does not honor uPnP])