[WPenvy]

Im only 4 days into my cycle and "System" has used 931MB. What the actual F**K?!

I assume most if not all of that was the 10586.63 update. Why didn't it use WiFi? And isn't the default supposed to not use data? The setting isn't under advanced options....

Ridiculous.

[jeffgeno]

I have it even worse, 1.45GB in a couple of days. I couldn't even keep the battery charging without turning off data. Now I'm having trouble even maintaining an LTE connection. I tweeted a screenshot to Gabe Aul and didn't get a response, but this is a major, major bug. I'm going to have to roll back to 8.1.

[BryceMD]

Turn off sync messages between devices in the messaging settings.

[mmcpher]

Supposedly its a glitch in the latest TP and will be fixed in the next, which is due shortly. It's strange, though. I even had some cell usage attributed to Sim 2, even though I don't have a second sim card installed.

[Rugish Dapeca]

It's probably related to this: Windows 10 mobile build 63 insiders may have data eating bug

[Chintan Gohel]

My system usage for the past month has been 500MB on wifi and about 30MB on cellular.
On the other hand, 6tag has used 2.73 GB in the past month over wifi and about 300MB over cellular

[WPenvy]

It's not message syncing because I turned that off couple of days ago and the number has increased. Significantly.