nested 3d layers half missing

I'm trying to make a 3d space that is a "wall" (an illustrator file) and a "floor" infront of it (same ai file).

I duplicated the ai file so it's 2 comps (wall and floor)

I put these 2 comps into a third combo comp. They're all 3d layers by the way. So I transformed the "floor" version to be flat next to the wall, like a big L. Looks great in top, left,right cameras, looks groovy in Custom View cameras as I spin it around.

But when I place this combo comp into a "stage" timeline comp, I only see the wall. No matter what angle I place a camera at, there is no visible floor.

What am I not getting about nested 3d layers? doble clinking back in I see the groovy 3d room. But not in the comp with the text and other elements...

-- Jim