I've been running a park on the Bumbly Bizaar scenario.
The paths were virtually spotless but I was getting most untidy park awards.
Looked at the benches and they were all smashed.
If I recall there usually is a thought bubble for vandalism but it's been a while since i've played the original.
I can't therefore confirm unfortunately if this is 100% a bug or whether it's just a gameplay mechanic.