I updated my Lumia 520 yesterday to Windows 8.1, everything's cool, love the new features, I've checked I have all the alerts, volume and stuff properly set.
When I am using other apps, I don't get notifications from Whatsapp, nor when the phone is locked. If I want to check the new messages on whatsapp I have to open the app. It is not even showing the number of new messages at the tile.
I'm using Wifi, I'm not using Cellular data plan, what could be the problem? I already rebooted my phone several times :/