Hi, I've run into a strange problem. My iPhone 5S is generating lots of data usage on both mobile and wifi, whichever it's connected to. If I leave it connected to mobile data, it uses around 100MB/minute, on wifi I haven't monitored but it consumes all the bandwidth of my home wifi. Today it used 400MB in an hour, during which I wasn't using my phone at all. I've rebooted the phone, disabled background app refresh, iCloud backup was done last night so that's not it, App updates are on wifi only, iCloud photos is disabled. I reset my mobile usage stats to find the offending app, but while the "Current Period" shows the data being chewed up, it doesn't show in the app breakdown below, nor in system services. Any ideas? Thanks in advance.