Norma Bates won't go in the basement!

KarilynMonroe2

Hello. It has been a while since I built a basement in a house with a foundation and I so I had to relearn how to do it I followed a video tutorial on youtube and after several tries I was successful in adding a basement to the Yates house in Midnight Hollow. I deleted the staircase on the main floor, deleted the floor tiles/foundation in a 3x6 area, put 2 walls in the ground inside the foundation space, placed the stairs from the ground to the basement, then deleted the two walls, brought in the foundation walls close to the new stairwell, then added the stairs to the main floor. Looks great. Didn't use any cheats and there is nothing blocking the top or bottom of the stairs to prevent routing but poor Norma just cannot use the stairs. I tried removing everything else in the vicinity bit by bit including all walls, doors etc but the stairs are just not routable. What did I do wrong? I did this exact house previously and it worked but I lost that save. I have the base game, island paradise and ambitions installed.