I’m upset about this as well, even trying to force it doesn’t work (without cheating/mods). I just had my Sim (a spellcaster) max vampire lore, meet several vampires, talk about them a bunch.. nothing. I did have a teen vampire (the daughter of one of mine) knock at the door around 1am, she stood there for an hour then left. Honestly, the save I have where I focus solely on occult’s is becoming so forced and boring. Mermaids don’t want to ever admit it (um I can see your tail), alien abductions are incredibly rare, and the vampires are “broken”. The one time Vlad broke in recently he just emptied my trash, loaded the dishwasher, played with some clay, then left. I used the club system to make vampire covens, and they don’t even show up when I send another Sim to their hangout.. so even my “cheat” isn’t working.