react-native: Geolocation can not watch the position.

Geolocation can not watch the position. It only updates when you go to homescreen and reopen the app. To recreate this problem, just use the example on React Native docs: http://facebook.github.io/react-native/releases/0.31/docs/geolocation.html#watchposition

componentDidMount(){
  this.watchID = navigator.geolocation.watchPosition((position) => {
      var lastPosition = JSON.stringify(position);
      this.setState({lastPosition});
    });
}

Using React Native version 0.31.0 & 0.30.0 on iOS.