The app is not currently designed to update immediately upon device wake or restoration of a data connection.
Currently, the app only updates on the set update schedule. So, if you have a 30-minute update set and the update would run at 9:00 a.m. and it is 9:04 a.m. and the device has no data connection and you activate the data connection at that time, it will not update until 9:30 unless you manually update or launch the app, which will update the widget.
The option to have the app automatically updated when the device is woken or the internet connection restored is something we're looking at for a future update, but we don't have a specific ETA right now.