So i disabled on ambientweather.net, and have info in my console. Rebooted, still no icon. Ill give it a little while.
As Galfert said, the by far most common reason for this is incorrectly entered information in the console, I've done it, terribly easy to make a mistake.
You mentioned that WU was updating with your data, so we have to assume that was coming from AmbientWether.net, which , you have now turned off. So you can verify now that WU is not updating, correct?
I would wait 24 hrs to see if it snaps in directly from the console.
I have also seen this happen when I use my AP as opposed to direct to my main router's AP (if you have multiple) , I would suggest , although this sounds weird and makes absolutely no sense, to restart your router.