I am having this issue. My Sims are freezing in place during tasks; it was worse before the most recent update. Sometimes, they would stay frozen for anywhere from 2 to 4 minutes (actual time, not the Sims clock, which continues to move; time doesn't stop). If I click build/buy, pause or go to manage worlds, they will usually unfreeze when I go back to the game.
I'm playing the PC version, and I have all packs/kits, etc. I use some cc but have removed it and checked, and this issue persists with or without mods.
This may be useful...
I systematically determined that one Sim in my household may be causing everyone to freeze. I moved the household to a new home, on a new lot, and found they still have the freezing issue. Then I moved two members of the household to a different new lot/new home, and they were fine, no issue. I then moved those two Sims back to their old lot/house, and they were fine, no freezing.
So I went about doing this repeatedly, adding one extra Sim each time and checking how they behaved on the first move, the second move and then back to their original home. I found that every time I moved the entire household to a new lot/new home (didn't matter where), they froze. I was able to do this four times without my Sims freezing (except when they all moved together into the first new lot/new home). The fifth time, I had Wolfgang Wilder (werewolf) in the group, and the household froze in each new lot/new home, as well as our original lot/home. On the sixth try, I didn't take Wolfgang, and they were fine, no issue. I did this one last time (no Wolfgang) with my final Sim and had the same result, no issue.
I then went to play with Wolfgang and found that he continues to freeze while doing tasks, and he is the only one in the household. Lastly, I invited Wolfgang to live with us, and as soon as he became a member of the household, everyone froze again.