On iOS, is there any way to see what the “Documents & Sync” system service is using cellular data for?
I’m using iOS 13.2 on an iPhone X, and would like to drastically reduce the amount of cellular data my phone is using. In less than a month, my phone has used 10.7 GB of cellular data. 8.5 GB of that is from “System Services,” with 7.9 GB coming from “Documents & Sync.”
Is there any way to see what is using all of that data, or to control what happens over cellular vs waiting for Wi-Fi? My battery also dies quickly, and assume that is related to how much cellular data is being used in background.
What I tried:
I turned off iCloud Drive syncing over cellular network yesterday morning and then reset cellular data usage statistics. Since then, Documents & Sync has used used 1.0 GB of cellular data .
I’ve had “Low Data Mode” turned on under Cellular Data Options for the entire month, which doesn’t seem to be helping at all.
I tried erasing all content and settings and restoring from backup. This may have helped slightly, but it still seems to be using large amounts of cellular data
Solution 1:
Take a look at "Wi-Fi Assist", which is found at Settings --> Cellular --> right near the bottom of the list. This setting uses your cellular data when Wi-Fi connectivity is poor.
This may account for cell usage even when you have iCloud Drive turned off.
Solution 2:
Running into this exact same problem, disabled every single option vaguely related to "data" and "iCloud" in the settings, and in my specific case tracked it down to WhatsApp leaching huge amounts of mobile-data (each time 1-2 megabytes within 1-2 minutes - and increasing - after disabling WiFi and enabling 4G).
If you run into this problem and have WhatsApp installed, try the following: Open the settings, click on your name/cloud-account at the top, select iCloud and in the list with apps disable WhatsApp (at the very bottom).
Note: There might of course be more reasons or other apps causing "documents & sync" leeching data. Interesting is that even if an App is disallowed access to mobile data, via writing to iCloud it can apparently indirectly cause usage of mobile data.
Solution 3:
I have the exact same issue. It started on Nov 9th and has continued since then pretty consistently. I had cellular data turned off for iCloud Drive, and I have background app refresh set to WiFi only. Also no iCloud photos turned on. I use Photo stream but have also set it to wifi only. I thought I'd started to troubleshoot the issue yesterday. I turned off my MacBook Pro (using the same iCloud account) before I left for work in the morning, and the documents and sync number didn't go up much all day. But today, I turned off its wifi before I left for work and it went up by about 400mb.
This is very frustrating not to be able to see what 'document is syncing' just a black box that's using insane amounts of data and forcing me to turn off cellular data unless I need it. Any troubleshooting suggestions welcome!