I've just started a new game with a faerie sim. They have the Plant Lover trait. The first and only thing my sim has done is talk to their rat. I immediately got the "Full Cycle Moment" buff for speaking with a PlantSim. My rodent is not a PlantSim. My household consists of one mermaid sim, one faerie sim, and one base sim. The welcoming party hasn't shown up and there's no other sims on the lot. My sim has not spoken to either of their housemates yet.
I own every pack and kit, sans the creators kits. I was not able to find this bug listed anywhere else. All my mods that aren't CC are quality of life for off-grid homes, farm animals, and cats.
