Early reports are coming in from select users that the latest Insider build for Windows 10 Mobile – build 10586.63 – may have a bug related to Messaging backup that causes excessive cellular data usage.

Starting a few days ago, users have begun to notice that their cellular data pushing towards 1GB in just a few days.

Over at reddit, a few users pinpointed the data leak to Messaging syncing, and history found in Settings. However, neither have been verified by Microsoft at this time although the company is evidently aware of the issue affecting some users.

As a precaution, users can disable Message History & Sync through the following steps:

  1. Settings
  2. System
  3. Messaging
  4. Disable Sync messages between devices

Some early reports we have received suggest that the above will address the problem. The bug does not seem to be an issue with the production build of 10586.29, but only for Insiders. On our Lumia 950 XL with the latest firmware and .63 release we do not see the data drain, but we also did not have Messaging sync enabled to begin with.

To check your data usage:

  1. Settings
  2. Network & Wireless
  3. Data usage
  4. Usage details (below the graph)
  5. Check Messaging and/or System near the bottom, which may be unusually high

At least one report has also noted a higher than usual usage of data by Outlook. However, we do not have many reports to confirm that one.

Bugs on the Insider program are to be expected, and users agree to the risks when enrolling. However, all of this may be moot as we are expecting an update to roll out today that may very well address this unusually high data usage. More on that shortly.

Via: reddit 1, reddit 2 Windows Central Forums