Preview over wifi never worked for me. There is something about it my firewall on my PC doesn’t like.
I had similar problem in Construct2, running C2 as administrator did solved the problem with preview. Never tried with GD because I never run anything as admin, no way, but you can try it and see if it helps. But in general I would advice against to run anything as admin unless you know what you doing and most importantly what the app does that you are about to run as admin…