Ideas
It's weird, but recently a lot more visitors have shown up when I come home from work, on my home lot. Usually I have the private dwelling lot trait in addition to all Trespassing Door Settings restricted, so it's something I notice every time when there's (f.e.) a young child sitting alone outside my house's doorway. This seems to be linked to coming home from work or another lot, in particular although I can't say what exactly is triggering it. I've had it happen both in the Worlds of Innisgreen and Willow Creek, so it's definitely not something Specific to any one neighborehood. Most of the time I return from the loading screen to a sim just barely on my properity outside (like in the walkway I build on my lots between the main streetwalk and my home proper f.e.), I could understand if they were in the streetwalk, that's normal, but for them to come onto my active lot is strange to me with the security settings I have.
I have nearly all Expansions, Game Packs, and Stuff Packs (except for 2 stuff packs), and a small assortment of kits (of which I only really use Bust the Dust, Little Campers, Pastel Pop, or the Swimwear and Ribbon-y(i forget what they are called) one)
I run on PC Exclusively, no Mods or CC currently installed, and hasn't been since before my last HDD Format so there's no influence what-so-ever from those. i run in Full Screen DX11(12?) if that's helpful, and make good use of pack settings and gameplay settings to tailor my experience to my liking. I tend to have like 1 main save, with a few supporting saves when I'm feeling awkward, in that main save are 52 Sims of 80, and the Neighborehood Stories are disabled for all "Played" Households.