Just to add to this report, I have similar issues with the freezing. The faves I add will show as a green heart for a while and then disappear, If i then refav an item the game will lock up completely with the spinning hourglass of death.
This only seems to happen on households for me, lots and rooms retain the fav icon.
I have all packs and have taken the step of ordering a new ssd, completely uninstalling the game from my PC (clearing all registry entries) and reinstalling everything from scratch to the new drive.
With a completely fresh install (no mods, cc or tray items added) the issue occurred again immediately.
I have also posted updates in game on a sim called ♥Gallery Issues Update♥ and others have reported the same problem.
When the game locks up the only option is to force closure through taskmanager or reboot (if you are not tech savvy).
This cannot be an issue with peoples installs, cache, saves or tray items as it occurred on a completely fresh download, it is definitely a gallery problem and one that really needs fixing
as constant lockups and crashes will drive players away from the game.