When sims have bought ice cream from the ice cream van they walk a step back and forth on the pavement a couple of times, and then they for some reason must take the bike and ride to a park bench far away to eat the ice cream. What could cause that?

I have the same issue. It is a nightmare! Not always, but certainly a lot, sims would pick up an ice cream and then take a taxi/bike to other side of the town!! Like, come on, I know sim AI is not the... sharpest tool in the robot's head, but this is ridiculous.

I think it has something to do with the spot where the van is parked. Maybe some invisible routing issue that causes the sim to calculate that the most attractive spot to eat its yummy is in the park, but not taking into consideration where exactly that park is...

Yeah, it's very annoying. Oh well, from now on my sims will use the ice cream maker.