Broken Mesh with Splitting WB

Hello Team,

I was having abit of problems with this mesh split. The results seem to be broken and I was wondering what the reason was. I have tried Rhino 5/6 and got no luck. I have tried recreating the original meshes with wb but that’s what seems to causing abit of problem.

Any ideas welcome.

Thanks (17.7 KB)
Rhino.3dm (4.0 MB)

Rhino 5 Model

rhn 5.3dm (4.0 MB)