Weather 2.0.1 not working in release mode

Building an app which is to include weather info. I have successfully gathered required data in an emulator and on a real device in debug mode (attached to PC via USB), but when I build an apk and install to a device it does not fetch data.
To rule out any of my code, I copied and pasted your example code to a new app and it shows exactly the same behaviour. In debug mode it lists weather or forecast on input of a valid Lat, Lon, but when I build an apk and install it just displays the circular progress indicator and 'Fetching Weather...'