Attach to base works in one condition but not in identical condition

[cbt990]

[barthbradley]

Identical?  Doesn't sound like it.  Post the file.   

[cbt990]

Okay, they actually arent identical.

Top slab cut is sub elements, bottom slab cut is void in place.

[barthbradley]

So, does that mean that is good now?  No issue?  

[cbt990 · Accepted solution]

I used Join instead of attach to base and it creates the same effect.

[barthbradley]

.