Stairs Are Broken

Hello, in playing with my household, I realized that all of a sudden, after having it work for hours, my sims couldn’t get up the stairs. They refused to get up with nothing on the floor in the way, and it was only when I extended the hallway the stairs were in did it work. For 30 minutes the stairs worked again and all of a sudden my sims had issues again. I keep having to increase the room size and then putting it back to get them to go up stairs and it’s super frustrating. Plus infants have been broken since their release so can we please get on that?