Resumed my save and suddenly all sims in my household were getting the 'Poorly Decorated' modifiers, no matter what room they were in. Previously all sims would regularly have positive moodlets in the same rooms and house.
I didn't change anything in these rooms, but I did add a basement to the house. None of the sims have been in the basement yet, and I double checked that I didn't accidentally change wallpapers or anything else. Every room upstairs has several decorations boosting environment.
The basement has 2 floors, the bottom one is unfinished due to lack of funds, but I fail to see how that affects the ground floor and second floors of the house.
Edit By Crinrict: Adjusted Title fit migrated bug report: https://answers.ea.com/t5/Bug-Reports/NEEDS-INPUT-Always-badly-decorated-moodlet-Patch-1-68/td-p/9720193
Generally bugs still open in the archive do not need to be re-reported unless you have new info.
