Game stops responding when I minimize Sims

Whenever I minimize the Sims 4 Window (I always swipe up with 4 fingers on the trackpad), it stops responding. 

I'll try to open it again, and the beach ball starts spinning but never stops. When I go to force-quit my apps, it always says that Sims 4 isn't responding in red. 

This happened constantly when University was released. Then when the last update hit, it was working again. Now, it's doing the same thing 70% of the time. This never happened before University.