Just want to share

If using Iphone, this can happen. Not sure which iOS but I think its the iOS9 and above. The feature is called Wifi assist. If Android than it shouldn't happen.

Here's a link Wifi Assist

Quoted from the website.
"The feature quietly swaps your iPhone from a wifi connection to mobile data, if the device judges that your 3G or 4G will be the speediest of the two connections. It's designed to stop endless load times when connected to a sluggish wifi hotspot or home network – but it can quickly burn through your mobile data, especially if you don't have an unlimited plan."

Also take a look at settings for each App. Some use mobile date in background.

This post has been edited by Raksaksa78: Mar 21 2016, 03:39 PM