The effect displayed in Vision Pro is inconsistent with the effect shown in the Game window.
These are my settings in Unity.
I found that if I switch to the Mac platform and build, the effect displays correctly.
I’ve been looking at your bug submission IN-89481. Using the project provided, it appears that the you only updated the HiFi rendering profile, which works great for stand alone. What wasn’t done was replicating the setup to the Performant profile, which happens to be what is set as the default for visionOS. Once that was copied over, stencil came out as expected.
Screenshot attached to show the settings and the rendering in the simulator.
Just to add to this, your project has the High Fidelity profile configured as the default in Project Settings → Graphics.
However, in Project Settings → Quality, you have the Performant profile selected as the default (in green). These quality settings override the default profile.
That meant that the Performant profile was the one being used for visionOS builds. When I tried switching to the High Fidelity profile, I saw the hole as expected (albeit with some weird lighting issues, perhaps due to HDR settings). As @joejo points out, copying the settings over to the Performant profile makes the hole show up there as well.