Sims cant do any water or snow activities

I haven't played in a few months, so I'm not sure when it started, but I'm confident it's the newest update. My Sims and none of the NPCs can interact with the water in Sulani or anywhere else beyond the shore, and they can't ski, snowboard, or sled on the snowy mountains in mt komorebi (or w.e its called). I play on a newer iMac purchased back in April, and my sister has the exact same iMac, but she didn't install the new update; she's just been playing offline, and her Sims can still swim and sail in Sulani while mine can't. 

On the iMac, I've turned off and removed all mods and script mods, uninstalled the Sims 4, and deleted the Sims 4 folder entirely to force it to create a brand-new one after reinstallation. Created a new base game family, and they still can't interact with the ocean past the shore or do any of the snow activities.

Someone said it could be related to marketplace items, so I uninstalled every expansion and Kit and Stuff pack and created a new family playing JUST the base game, nothing else, but still no resolution. I'm so annoyed and confused, don't know what else to do 😑