Re: I wish townies will stay in their own worlds
@bae281995 Those townies belong to the NPC's that fill up the game. The more packs you have the more these Sims will dilute in your game play. I think these appearances are intended. So I don't think it can be fixed. If you choose for the option to fill empty houses you will probably be able to see more Sims. Another option is to create more households and let these households live in your worlds.
Have fun playing. 😉