Additional Findings:
Mods are not related.
I moved the The Sims 4 folder out of the Documents directory and allowed the game to generate a new one. Even in a completely fresh setup (no mods, no saves), the same issue occurred.
Changing households does not resolve the issue, so I do not have any usable save data.
CAS and Build/Buy modes work without problems.
Behavior of the freeze:
Sims freeze in place but sway slightly, looking around, sometimes laughing or making noises.
Time continues to pass, and needs decrease normally.
Cars still drive by and townies spawn.
Active Sims and townies frequently start dancing on their own and continue until reset. After resetting them and sending them home, a large number of Sims suddenly appear on the lot as if they were queued up.
Observed actions:
Clicking on a stove or fridge to cook deletes the task immediately, and no action occurs.
Sims autonomously sit at a dining table, but no food is present. A “meal” task shows in the queue, and they freeze in the chair.
They can take a vegetable from their inventory and begin eating, but freeze midway.
Unable to cook, they attempt to dive into the trash for food but stay in place, floating and flipping unnaturally.
When picking up a dish or trash to clean, they freeze in place.
When autonomously cleaning a sink, they scrub at an incorrect spot far away, polishing the air.
Watching TV works correctly.
When trying to read a book, the task shows in the queue but no book appears in hand.
Directing them to sleep in a bed does nothing.
Toilets work normally, but baths/showers do not — the task remains in the queue and the Sim freezes.
Using a mirror also causes them to freeze, with the task staying in the queue.
Directing them to fish or collect items makes them stand still while skills unlock, without actual movement.
Digging for rocks works.
Jogging starts correctly, but the Sim stops midway and cannot return home.
Attempting to talk to another Sim causes them to freeze. The conversation task does not complete, and the game briefly pauses when issuing the command.
Using the phone to travel makes them talk endlessly, but the travel action never happens.
The same occurs when trying to use the phone to join a career — they keep talking, but no career is assigned.
Additionally, I noticed that the Aspirations panel has changed to the same layout as the Career panel. I’m just wondering if this might be somehow related.