Basically, a small gap in the navigation mesh causes the AI (both adults and children) to think there is an impassible wall in the hallway unlocked at the end of the tutorial that's opposite of the starting room. Basically, AI will always be stuck on one side of this wall and cannot pass to the other side. You'll notice this when trying to lure some children from the party room into the long room at the far back, where they refuse to follow you any further. This is also what results in adults sometimes going and hugging the back corner of the staff-only room, because the point they selected to move to is on the other side of the wall and they are trying to get to the closest possible position to that point.

In the meantime, since the bug is not completely game-breaking, it won't be receiving an immediate patch, however expect it to be fixed in the near future.