Auto Equip bug

I don't have the Auto Equip setting enabled in my game, but after trading with someone, i noticed that the ring i just bought was automatically equipped since i didn't have anything in that slot

I used to have that setting enabled before, but it's been a while since i turned it off, maybe it's some kind of "vestige" or something like that?

Unless this an intended feature, i don't think this should have happened right?