Rhino chamfer issues

Hello, I’m Clément. I’m designer for Cardboard furnitures.
I jump to artiosCAD to Rhino. i Love rhino and I’m still learning.

To simulate V-Cut for folding board. I use the command chamfer on the solid. When it’s simple rectangle, it’s works like a charm… But when it’s became more complex. I have issue with the result of the chamfer on a solid. the chamfer edge is open.

Video Rhino Chamfer

do you have an idea of what happens and how can I solve it ?

Thank you.
Clément

maybe the issue is the size of the chamfer. try making the extrusions taller than you need and after making the chamfers, cut the extrusion to the final height