I own it as a community lot, I also regularly clear my caches before I start the game so that hasn't helped so far, all I found via google was topics from years ago where some people had this problem, mostly with the pool in SV where the entire floor space was covered in dirty plates.
Of course they all suggest mods to sort it but that isn't an option as it's a dynasty. By rights I shouldn't even own Plaza park as I put a rabbit hole on it but the game didn't sell it off like it normally does, I might get rid of it then put it back to see if will sell it now, maybe it will start cleaning that lot then.
I bought that lot post patch, the other two pre patch but I'm not certain if the mess started after the patch or not, possibly after but if it was a patch issue I would have expected more people to have noticed this, I think my game is just getting to the buggy stage now after so many generations
On the plus side my founder has the run bug so that's a good one while it lasts.
EDIT: replacing the rabbit hole still didn't make it sell, odd but not a problem really, unlike the spoiled food.