Direct message sent to all channels

Summary

Direct message was broadcasted to all participated channels.

Steps to reproduce

How can we reproduce the issue (what version are you using?)
It only happened once, and we have yet to reproduce this.

Mattermost Server: 3.6.2
mysql Ver 14.14 Distrib 5.7.17
centos-release-6-6.el6.centos.12.2.x86_64
Client: 3.5.0

Expected behavior

Describe your issue in detail
User A replies User B in a direct message. Only User B receives the message.
The message is private, hence should only be sent to User B.

Observed behavior

What did you see happen? Please include relevant error messages and/or screenshots.
User A replies User B in a direct message. User B received the message.
However, the message was also sent to all Channels which User A has participated.
All other user sees the message from User A in the channels

User A is in Channel X, Y and Z. Now User A Edits the message in Channel X,
the change is propagated to all the other channels sent.

Hi @etcy,

Thanks for your report!

Mattermost 3.8.0 has been released and I was wondering whether you could try updating your installation to the latest version?

It seems the issue is not easy to reproduce but please let us know whether you see this happening again after upgrading to the latest version.

Thanks!