On previous versions of autocad I used all views to draw lines and rectangles to produce 3d models, but now when i try it they only come up as horizontal lines.
2004 could do it. I was able to draw in all views, extrude the parts (walls, windows etc.), then join them together using an angled view
In your example look at the UCS, the X and Z are showing, change to an iso view or change the UCS so the X and Y show.
When drawing 3D in AutoCAD it is best to have at least three viewports showing, with one of them in an iso view and the others in a front and right view, or top, etc. so you know for sure where you are drawing in space.