Steps to reproduce the issue

1. In User Manager, click on a user account, click Basic Settings, and change the Editor.
2. Save & close the user account.
3. Edit another user account and change the Editor to a different setting.

Expected result

Each user's Editor setting should be retained.

Actual result

Each user is set to whichever editor was most recently set.

System information (as much as possible)

Joomla 3.6.2
Apache HTTPD
PHP5 FPM
Ubuntu 14.04

Additional comments

I noticed this following the most recent update. I do have the Switch Editor plugin installed, but I disabled it while troubleshooting the issue and the issue still occurs.