Does anyone know why this happens & how to fix it?

Whenever I add a platform to a room, if I have roofs in the middle of the structure they appear inside the room whenever I add a platform. Even when I add the walls back. I tried deleting the roof and adding it after the platform but still it comes through the room. This happens often with my builds and I don’t know how to fix it other than to resize the roof but then there’s times, like with the hexagon like shape there, its difficult to resize the roof without leaving a noticeable gap between the roof & the building. Anyone know what I’m doing wrong here or how to stop this from happening? I have bb.moveobjects cheat on too. I attached a photo to show what I mean 

im on console: PS5