I did a little more digging, and here's what I found. When connected to the network in question, I get numerous errors in the browser console like this when loading the pro home or campaign pages:
XMLHttpRequest cannot load http://vanguard.moz.com/pro-home/campaign-list-lite/prod.3938937. Origin http://analytics.moz.com is not allowed by Access-Control-Allow-Origin. (home, line 0)
I do not get those errors (at least I have not thus far) when connected to other networks. I don't know much about the network setup here, but I do believe there is a proxy in place.