[IL] Excessive amount of sand sculptures when visiting beach lot

This is happening to me as well. It happened to me yesterday, and I was hoping it was just a one off glitch, but it's happening again today. (I don't have For Rent, nor Hobbies and Businesses, if that's relevant.) I play on PC. 

Again today, as soon as my sims arrived at the beach, numerous sand castles started immediately spawning. I paused the game quickly and looked around. There was one Lifeguard, one Beachgoer and one Sunbather. No Sand Artist on site yet. This happened twice at Ohan'ali Beach. I have no residential rental properties in the neighborhood - or on Sulani at all. 

So then I traveled my sims to Sand Simoleon Beach and let the game run for a couple of minutes. It did not happen there. Beachgoers and Beachcombers showed up and started doing their thing. No Sand Artist showed up. No sand castles spawned. Everything seemed fine. 

So then I traveled my sims to Baia Dell'Amore Beach in Tartosa and nothing happened there either. No sand castles spawned upon arrival. Some Beachgoers and Beachcombers showed up. Then a Sand Artist did arrive. Still no sand castles spawned. Nor did the Sand Artist build any. Everything was fine. 

So from there I had my sims go full circle and traveled them back to Ohan'ali Beach where they started. After arriving, the sand castles that had spawned earlier, slowly disappeared one by one. Weird. 

Just had this happen to me as-well, an npc sim began digging autonomously in the sand and the sandcastles would appear and then gradually disappear before appearing again.  

Just found this bug. Also on Ohan'ali beach in Sulani. Weird but so far harmless... I think...

This still on going, I've only noticed it happening in Mua Pel'am after changing the empty lot to a beach type. It's honestly entertaining at the rate they were spawning

I'm on pc and no residential rentals in this world

I have the same problem. I don't have cc or mods and I uninstalled For Rent.