I believe this is a completely different scenario.
Even if the orthographic shadows were working.
You are using the orthographic camera from the side, so you can’t even see the surfaces that are receiving the shadows.
You can’t see the floor because the camera is completely parallel to the ground surfaces.
To see them you would have to angle the camera a little bit.
I haven’t tested this bug in a long time, so I don’t know if it’s been fixed, but I doubt it.