NPCs moving into empty lots

Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? Often (50% - 99%)
What is your current game version number? 1.51.77.1020
What expansions, game packs, and stuff packs do you have installed? Expansion packs: cats and dogs, city living, get famous, get to work, get together. Game Packs: dine out, jungle adventure, vampires. Stuff Packs: bowling night, perfect patio, vintage glamour.
Steps: How can we find the bug ourselves? In Newcrest, In the lots named, The political Instrument, The Influencer and Oak's Hidden Alcove. The sims that are currently occupying the houses are not made by me. (Omar Choukri, Genji Maeda, Denzel Cabrera) I left those houses empty of sims on purpose after creating and styling them. This has happened before and I thought I had fixed it by evicting the previous sims, changing my password, changing my id, and adding security codes, however it has happened again. The sims that appeared also look to be gaining skills (they aren't being played by me). In addition to this, last night, my "out of this world desktop computer" and "gotta stream em' all streaming drone" disappeared while I was playing the sims in that household (the sims in that household I did create) that lot is named "feelin' blue starter". I believe it may be connected since it occurred around the time new sims showed up.
What happens when the bug occurs? Sims I didn't create or move in appear in the household lots I create and leave empty. Those sims seem to be gaining skills as if they are being played. (I haven't checked any of the other worlds for anything similar)
What do you expect to see? No sims in the houses I've left empty. Thank you for looking into this.
Have you installed any customization with the game, e.g. Custom Content or Mods? Never used.
Did this issue appear after a specific patch or change you made to your system? Neutral/Not Sure 

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