I get an application independent message overlay "check your connection and try again" on the screen as soon as I turn my data off. I don't remember seeing this earlier or maybe I just never noticed it. But now it's bothering me whether some application is constantly connected to internet without my knowledge.
I checked the data usage in Settings and nothing suspicious there... but still, it would be great if someone can check on their phone and report the behaviour.
Btw I'm still on PureX v4.
TIA
~ff