Last night my Iphone suddenly used a LOT of cellular data while connected to wifi

[SlitheryDee]

I went to bed about midnight last night. As usual I set my phone on the nightstand next to me. At about 1:00 AM as I was almost asleep I heard my phone receive a text message. I didn't check it. This morning at about 6:00 AM my phone woke me up with another text message. It turns out that both messages were from verizon warning me that I had used up a certain percentage of my data cap. The message at 1 AM warned me that I was at 75% of my cap, and the one at 6 AM warned me that I was at 90%. So in that 5 hour period something was using a lot of cellular data. I'm fairly certain that whatever it was started a while before that because there's no way I should be getting that close to my cap with two weeks left in my cycle anyway.

WTH happened here? I was in range of my wifi, background app refresh is turned off, and every relevant app on my phone is set to use wifi only when uploading or downloading data. I can't find anything on my phone that might be responsible. Has anyone seen this behavior before? What could have caused it? I have an iphone 5s.

 

[vshah]

check your email outbox, anything there?

I once had an email with a large number of attachments attempt to send over and over using cellular data, but it never succeeded because of ATTs crappy network. this was on my father-in-law's iphone 4s.

 

[openwheel]

NSA got all your info through iPhone

 

[eelw]

Check under your Cellular menu for the Use Cellular Data For section. See which app had a data spike. Also turn off any apps that don't really need to be used when on cellular data only.

 

[SlitheryDee]

Check under your Cellular menu for the Use Cellular Data For section. See which app had a data spike. Also turn off any apps that don't really need to be used when on cellular data only.

I see 1.5 gbs next to the video app. I suppose that was it. It makes some sense because I started downloading a movie earlier that day and then stopped the download. It must have continued on over the cellular network anyway. I don't know why it would do that since I was on wifi at that time. I have noticed that the phone likes to turn off wifi when it goes to sleep, but it would seem stupid in the extreme to automatically continue the download of a large file like that after turning off the wifi connection. In any case the movie isn't present on my phone, so what it was trying to download clearly failed. That's an extremely annoying behavior.

 

[Red Storm]

NSA scheduled backup.

 

[vi edit]

5s? My wife's 5s was horrible about switching over to Wifi when she got home. It would continue to stick to LTE even though I've got coverage across the whole house. Even if you forced wifi it would still default back over to cellular.

I had to go in and delete all of the associated networks on the device and rebuild them. It's been ok since then. Never had this issue with either a 4 or 4s. I think iOS7 has some bugs to it for remembering and cutting over to wifi as it was doing this at work to her too.

 

[SlitheryDee]

5s? My wife's 5s was horrible about switching over to Wifi when she got home. It would continue to stick to LTE even though I've got coverage across the whole house. Even if you forced wifi it would still default back over to cellular.

I had to go in and delete all of the associated networks on the device and rebuild them. It's been ok since then. Never had this issue with either a 4 or 4s. I think iOS7 has some bugs to it for remembering and cutting over to wifi as it was doing this at work to her too.

Mine started out excellent, but it seems to be a bit sluggish when changing from LTE to wifi now. I should probably just reset the network settings and start over. I hope I don't have to do this often though. :\