As the title says, I am unable to place a secure wooden door in a 2x1 opening in my wooden walls where there is a metal trussing block as the floor.

Example: This is front-view of the opening. w = wood, o = open, m = metal trussing. A wooden floor is attached to the metal trussing.

wwwww
wwoww
wwoww
mmmmm

Not sure if this is a bug, glitch, or intended, but I figured since I hadn't seen it reported yet, I thought I'd report it. No crash or errors shown, the door simply wouldn't allow itself to be placed. I tried on 3 different openings as I have an entire room, elevated, with 4 openings. All have the same exact set-up, with wood on both sides and top, 2-block opening, metal trussing below opening.

wwwww
wwoww
wwoww
mmmmm

wwoww
mmmmm

wwoww

mmmmm