Mac User. Sims 4. This has happened on both the Origin and EA apps.
Whenever I move a family into a house, the holiday decorations are always up regardless if its a house I built or was supplied by the selected world. I can build a house on a lot. Save. Move in a family and bam—holiday decorations are on the fences, eaves, all of it. I then have to place the Holiday Decoration Box to have a sims take down the decorations.
Idk if this is a bug or not but it happens every time without fail.
I recently had it continuously hang the decorations whenever I went into build mode and then back to live mode. That lot was a residential rental lot and would put decorations on all four units I had on the lot, even though I had one family living in one unit (not owners of the res. rental lot).