Brep Split ERROR(solved, it was my mistake, I'm sorry)

I found Brep.Split has no problem.
I missed when split returns nothing(empty array).

I hope another friends do not misstake such as I did. ^.^

spliterror.3dm (489.2 KB)

Hello! .^^
I’m in trouble with splitting brep.
I found BREP split result sometimes some missing part of it.
I uploaded the file and image.

I made splitter as below, x,y,z directon(1/2 of boundingbox)