Mesh Split doesn't work occasionally in WIP

I tried to split mesh_terrain with mesh_to_punch_hole (which can absolutely pierce mesh_terrain)

But some cases didn’t work in WIP and the output was original mesh_terrain.

This image and file is an example of the case that DIDN’T work at WIP but worked in Rhino6 Grasshopper.


punchhole.gh (27.7 KB)

Is there any way to avoid or go through this situation?