Subtractive brush unreliable in 4.0.2.

Loving UE4 so far but I’ve noticed a problem. The workflow I was show was to place a single BSP brush and copy/resize it for new walls.
The problem is some way down the line I’ll need to subtract something, and copied brushes will not subtract even after changing the mode to subtractive.

I also noticed this when copying a wall with a subtractive brush in it… the copied wall’s subtraction no longer worked (they may have been grouped I can’t remember).

Using 4.0.2. Was this address in the update, didn’t see anything in the release notes? I’m already in the negative bandwidth so don’t want to update for no reason.

Did you try building the geometry?