The comment about the service startup order is interesting. If this isn't explicity set then I could imagine a race condition between htcondor and the network service which would explain why some machines get the correct interface address and some get the loopback. I'll get back to you when I have some more information.
On Linux, this was the cause of a lot of problems with HTCondor advertising loopback addresses, particularly because some distributions considered the network to be up when the loopback interface was ready, not when DHCP (or whatever) had finished. I don't know what the case is on Windows.