Godot version

v4.0.1.stable.mono.official [cacf499]

System information

Windows, Vulkan

Issue description

Adding (or subtraction) two meshes with CSG seems to erase verts from the mesh incorrectly

Steps to reproduce

Create some mesh and use CSG to add/subtract - if you align a vertex just right it seems to cause this issue.
I can "avoid" it by bumping the location by a fraction but I'm really trying to have a perfect alignment of element for the game I'm working on.

It seems like it happens more easily if your vertex coords are integers

Minimal reproduction project

HoleMissing.zip