Lagging actions in Simulation Mode

My issue with TS4 is the same one many people here are having. Lately, in live mode, my Sims take forever to start an action—opening the fridge, using the phone, basically interacting with the world in those “on click” interactions.
I have no problems with freezing or with buy/build mode, but in live mode it’s become impossible to play because from the moment I click until the Sim actually does the action, it takes several minutes.
I’d like some help or possible solutions because I’ve tried many things and nothing works. It’s not a mods issue either, since I’ve even tried playing without them (and the ones I use are basically only clothes and hair, no scripts).
My laptop can run TS4 on high/ultra without problems, I have enough memory, updated drivers, etc.