Product: The Sims 4
Which language are you playing the game in? Svenska
How often does the bug occur? Often (50% - 99%)
What is your current game version number? 18.104.22.1680
What expansions, game packs, and stuff packs do you have installed? All except Spa Day, Outdoor Retreat, My First Pet Stuff and Digital Deluxe.
Steps: How can we find the bug ourselves? Not sure, just wait and see I guess.
What happens when the bug occurs? The hygiene meter doesn't decay for at least teens and adults. I haven't played with any children or elders in a while. Toddlers' hygiene meter seems to work but goes down slower than what I remember (I don't play with toddlers very often, so I could remember it wrongly). The hygiene goes down when a sim slips in a puddle of mud, but other than that it doesn't seem to go down at all.
What do you expect to see? That the hygiene meter decays normally.
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? Yes
Please describe the patch or change you made. I recently got 15 of the stuff packs and Snowy Escape, and installed them all within some days from each other. I think the problem appeared after installing Snowy Escape (I installed and tried out the stuff packs some days before installing Snowy Escape), but I'm not sure because it took a while before I noticed this problem, so it may have been there before Snowy Escape. It could also very well be one of the recent patches causing it.
None of the sims have any traits that would affect their hygiene. Two adult sims with the traits Muser, Domestic, Vegetarian, Loves Outdoors, Green Fiend, Super Green Thumb, Companion and Chopstick Savvy, and one teen with the traits Quick Learner, Loves Outdoors, Green Fiend, Chopstick Savvy, Top-Notch Toddler and Mentally Gifted. The teen also seems to have the Angelic trait (the trait she had as a toddler) when I look at her Sim Profile via the Relationship Panel, but it's not visible in her Simology Panel. I haven't cheated to give them any of the traits (though now I wonder how the two adults have both Domestic and Muser traits, because those are bonus traits from aspirations and I'm very sure that I didn't cheat with the traits, I think they started off with the Muser trait). I did try to add the Proper trait to the two adult sims, with cheats, which didn't work for some reason, but I think the bug was already there when I tried this.
They don't have any lot traits now, they earlier had the Off-the-Grid and Great Soil lot traits, but it is some sim-weeks since I removed them.
Active N.A.P.s are Power Conservation, Self-Sufficiency and Water Conservation.
I've turned off the lifestyles in the settings.
I have been testing this a bit more. For example with a child and with other adult sims, both in the save file I first saw this and in other save files. Their hygiene meters don't decay except for when they do certain things, like jogging (but I feel like it goes down slower than before, but I'm not sure) and if slipping on a puddle of mud. Otherwise the hygiene meter stays the same all the time. I tried with a bunch of different sims, with different traits, lot traits, active N.A.P.s etc.
Another thing I noticed with one of my sims is that even though her hygiene meter is in the top, and she didn't have any stench around her, her room mate (as in someone living in her home without being in the household) left an angry note saying that my sim never showers and is stinking. I don't know if those notes are actually caused by certain events or if they're just random, but if they're supposed to happen when a sim actually stinks it's odd that she got the note when she hasn't been stinking for weeks. Anyway, I haven't seen any sims doing the "Something stinks" animation around my sims, so I guess that they're not stinking.
And yes, I have tried to repair the game, and it didn't solve this at all.