3D View
Go here https://forums.autodesk.com/t5/autocad-architecture/3d-view/m-p/9446075#M17517
Click on the REPLY button
scroll past the message box the drag and drop your file here, when done click POST
There are only two Walls in your file, the two you added and that display correctly. What appear to be Walls in plan view are anonymous blocks, composed of lines and, where present, hatches. The 2D "Doors", plumbing fixtures and appliances are also anonymous blocks. I assume that the 3D Multi-View Blocks and one 3D Window that are in the file were added later, as well.
Was this drawing file produced from an AutoCAD Architecture file that was exported to AutoCAD?
In a test file of my own creation, I played around with various export options, and was unable to recreate the state of your current file. The only way I was able to get Walls as blocks was to use the AutoCAD EXPLODE command on all of the AEC objects (Walls, Doors, Multi-View Blocks, etc.) I would think you would remember it if you had run the EXPLODE command on all objects, so that may not be what happened here.
However it happened, those objects are no longer AEC objects, so there is no tweak to the display settings that will have them present themselves in 3D when viewed from a non-orthogonal view direction.