hi ayla5421, I used to have this problem all the time. It turned out to be my laptop overheating. Once I got a better cooling fan to sit under the computer then this didn't happen. I am not sure if you have the same cause I did. But it might help.
I also use a laptop to play the sims (in real life lol) and have this issue. A good workaround that works for me is just pausing the game when the sims just stop moving. This helps things catch up. Usually there are thought bubbles or moodlets pending or actions pending in one of my sims' queue that are delayed for whatever reason. Pausing for about 10 seconds when this happens usually does the trick. I have not tried better ventilating, but I will!
