Zoning Fails on Some Wi-Fi Networks?

[El Furioso]

Everything works great on my PC laptop when running on my wi-fi network at home, or at Starbucks, or off my phone when I have it set up as a personal hotspot. But I've found some open networks (like in a hotel) will freak out. I can log in, select a server, select a character, but the game hangs after character selection and eventually returns me back to login.

 

Any ideas? Is there something I can adjust on my laptop to compensate for what I'm running into with some of these networks? Or is it solely on the network's side, and am I out of luck?