Random Sims moving in all lots

I mentioned this in the past but after playing for a while, suddenly a bunch of randomized Sims are created and are suddenly moved into every lot in my game.

Now, before you mentioned the neighborhood stories, I had it on before and tested to see if it was that what caused the issue. My guess was that it was that which caused that, but I'm not sure anymore about that. For a couple of weeks, I kept that disabled and never touched it. I just played yesterday and I only made a couple of households, built a world in newcrest, played for a little while. Then, boom, every single lot is filled with randomized Sims.

I didnt even delete any sims, or customized any Sims. I kept everything the same except newbies and the households I created. Its frustrating when i want to travel and see that happen and even when I edit it, it comes back.