From time to time FB roll out a feature to some users, that auto-tags your FB friends in photos that you upload to your wall or to groups.
This feature can be helpful to some users, as it auto-recognizes the friends using the smart FB algo.
But for other users, like marketers, this is really bad, as we don't want our friends (or our other accounts) to be auto tagged.
To fix it, just go to each one of your accounts' settings,
to the timeline and tagging tab,
and change these 3 settings: