Sims and cats randomly walking off grid lots in straight direction autonomously and this includes ending up walking through water - it's like they are walking on ground and can be seen but there is water above them including world maps. I don't use Mods or CC. PC platform. Has also happened where they were standing at the bottom of swimming pool and fully clothed in everyday clothes.
It's been a known ssue to The Sims 4 team for at least a year now. I haven't experienced it my self since that one time but every now and then I see others posting about it. I exited and restarted my game and haven't had that problem since then so far. Good luck. 👍
The Sims Team
