My N9 cannot stay connected to my mobile internet connection(3G) when it is idle..like when I leave the web app or wazapp running in the background. It stays connected only till I constantly open some webpage or keep on chatting on wazapp! Same for wifi! And sometimes it disconnects itself even when I'm using web app.
Any suggestions?

Thanks in advance!

P.S - Already enabled the allow background connections in the settings menu.

Check out your phone settings/battery/power saving modes...if it'set on, than it will disconect from network if it's not using it any longer.