Composite Walls with finishes not connecting properly

[MrSoleil]

Any idea why these two don't connect properly? Concrete Building Material set to 900, CMU to 800. Saved as cores in composite walls. All else is less of a priority in BM and saved as "other" & "finish". Walls on the same layer. 

The finishes should connect, but the concrete structure overrides them. 

[LeeJaeYoung]

Are you talking about this?

[MrSoleil]

Yes, seems to be exactly the case. Solution? 

[LeeJaeYoung]

solution??
The blue line at the bottom is only sent down to the end.

[MrSoleil]

Oh, OK sorry, I spoke too soon. Indeed not the case! The walls are connected and the finishes should show outside but for whatever reason the concrete overrides them in my case. 

[LeeJaeYoung]

The reason I'm shortening the text and sending only images is because I'm not an English-speaking person, so I'm afraid I'll be wrong with the explanation.
Are you saying you can't do that now?