Double Zhaleh Amani
I recently repaired my game. My sim was having an issue with his romantic preferences changing. That issue was tied most commonly to Zhaleh Amani. While testing the interactions to see if it would happen again, his preferences didn't change. But she did spawn a doppelganger.
The new version of her stood where she normally stands in front of the information board. And the version that my sim is friends with walked until she disappeared. Then she respawned in a new outfit and attempted to kiss my sim under the mistletoe. I cancelled that interaction because I did not want them to build a romantic relationship. When I checked his simology panel, everything was good.
I left that lot to complete a fable with another sim. And when I came back to deliver the item to Care Ren, Zhaleh Amani had spawned another time.