Small Business : customers cross the house to leave the lot

My sim recently opened a small business (game bar) and customers are crossing walls and residential parts of the house to leave the lot. 

The house is divided in two parts: the left side is the residential part where my sim lives (the rooms are properly set for this) and the right part is the game bar where rooms are set as public. The two parts communicate with doors. The front door opens to a hallway that’s set as public.

Customers enter the house via the front door, use the kiosk to pay their entry then go to the game bar, everything is fine. The problem occurs when they leave the game bar and the lot. Instead of using the front door to leave the house (like they did to enter), they cross the house, entering the residential part of the house and disappear in front of the outer wall (aka in the middle of my sim’s living room).

Any idea what might be the problem?