We'll revisit this once you are streaming and listening properly.
There is nothing you should need to do. This sounds like what happens if you have it already running and switch networks; or you're on a very slow network. Did you change to wifi after you opened the app? Restarting the app should fix this. To be totally sure there is no rogue or zombie processes left from opening and closing - I'd recommend you try rebooting the phone; connect to your wireless; then start pyPianobar and see if it starts working.