UPDATE: Can't change color on 1 wall for this FILE ONLY

[designer468]

UPDATE: I've tried everything to change the color on just one wall. I've created a fireplace wall and want to make it stone.  The material can't be changed for that one wall. I just experimented to see if I could do it on a different file and the paint for 1 wall works fine.  So there is something wrong with this attached file that it won't allow me to paint a single wall.  Could I have triggered a default setting that doesnt allow single colored walls?

 

UPDATE 2: The issue is only happening in the rooms with the raised vaulted ceiling.  In the rooms with the 8' ceilings, I can paint one wall only.

 

I'm trying to change the wall material on just one wall.  I'm trying to create the effect of having reclaimed wood on one wall.  I'm using Lap (weathered) Sliding as my material.  I only want this on one wall.

 

 I open up the wall that I want to modify and I change the wall covering to the Lap.  Nothing happens. So then I tried changing the "Materials" for the Exterior Wall Surface and the Interior Wall surface to Lap.  The result was just the edge of the wall being modified (you can see the Lap on the edge of the wall).   I'm also getting weird stripes on the wall. 

 

If I use the spray can, then the wall changes.  Unfortunately, it changes the material for all the walls in the room.

 

I just tried using the Spray Can but changing the type of cans.  Tried C, O, R and P.  Didn't work.  :-(  Either the entire room changed or nothing changed at all.

designer468_house-2c-soffit.plan