I am having a similar issue. My Sims are also freezing in place during tasks; it was worse before yesterday's update. Sometimes, they would stay frozen for anywhere from 2 to 4 minutes (actual time, ...
MargeKinson If the "new" version you passed through the Gallery is intact, then whatever was causing the original's issues doesn't pass through the Gallery, which is good but also not helpful if you don't want him to lose his history. You could reconnect his family tree with MCCC if you want (and if you're willing to use mods in general).
You could also remove everything from the old one's personal inventory and exile him to another lot for a sim-day or so, including a save/quit/reload, hoping that the game resets whatever is wrong with him. And if you are in fact willing to use mods, and this doesn't help, there might be another way to find and remove whatever info is causing him to freeze.
I did as you suggested and removed Wolfgang's inventory. I noticed something strange when doing so. I was able to sell everything in the inventory, except The Slablet, so I gifted it to another Sim. When I did this, I noticed a bunch of papercraft projects that were not in the inventory and could only be seen when 'friendly gifting'. Wolfgang had about 36 of these hidden items, one of which read debug. I had to gift these to random Sims to get rid of them all. Then I exiled Wolfgang and waited a couple of Sim days before inviting him back home.
I'm happy to report that after playing several times and for several hours, it seems my freezing issue has gone. I'm not sure if it was the collection of strange hidden inventory being removed or the exile (or both), but things are looking positive.
I found that all my Sims, but one, had some of the hidden papercrafts on their person. I got rid of them all and removed the papercrafting kit from their home (just in case). I've attached a photo of the papercrafts in the friendly gift section (it shows the confusing origami mishap image, but says it is a card, a mask or a papier-mache item).
I really want to thank you for the time you've spent helping me with this. I very much appreciate it.