After doing further testing on this, I've determined that the game/AAU isn't emitting the correct event for that interaction for some reason. It either doesn't emit anything at all, or it emits an event for a completely different interaction. I've been logging all interactions NPCs use towards the PC, and as an example it logged that an NPC was about to do the "Spread a good rumor" interaction, but the interaction they actually did was asking me to meet them somewhere.
It's like they originally start to do some other interaction, and then for whatever reason the game makes them do something else instead. I know modules will sometimes redirect interactions, but I would also expect an event to be emitted for the new interaction as well, but there's nothing. And given that you don't play with many modules, It seems more likely that this is some weird game/AAU behavior.
Since it seems to be impossible to accurately determine when an NPC is actually going to use that specific interaction, I'll probably just remove the handling of it from the module next update.