It's happening again! My WhatsApp is no longer receveing messages on the background, I need to open the app and wait for it to connect. Got so many people pissed already I didn't reply, lol. Happening after the Cyan and DP updates too, not sure if it's because of that.
This app is obviously underdeveloped and not suitable for 8.1, it doesn't even display proper notifications with title, like the native SMS and email, for example, they show a title and a brief text for each notification, where WhatsApp doesn't do that, just bloats the whole notification center.
Just reinstalled the app and it said it is having "Connectivity problems" and asked to reboot the phone. The phone was rebooted many times earlier, let's see if it's fixed now.