Sims constantly resetting themselves

This is an issue that happens sometimes. But as of a couple days ago, I've noticed it start to happen a lot more often.

When I tell a sim to do something, they will be on their way. But then suddenly, it is as if they reset themselves (like you would manually when you click Reset Sim but they do it on their own). What I mean is: They suddenly morph to stand in the neutral position and any queued actions are completely removed as if they were never there.

I have also noticed this happening with non-played sims. Obviously, I can't see if they have actions queued or cancelled. But I have noticed them abruptly stop whatever they are doing as if someone has just reset them.

I don't have any mods or cc and my game is up to date.