My sim keeps going to build sand scultpture together while painting

Is this issue may be related with the bug that sims keep playing for basketball while painting?

He keeps going for building sand sculpture and there's another sim was building sand sculpture on this community lot in Sulani. He did this for 5 to 6 times, and eventually, I sent my sim to home lot. There's no problem to paint on home lot although his home lot is surrounded by sand.