Hole in landscape, not working?

I’m trying to create a bunker with its entrance nestled into a hill, and the rest inside the hill… I’ve looked at a lot of questions and answers concerning this, and followed the specified solutions given… but there is no sight of the hole at all… I might as well have no tool selected and end up with the same result as I do with the visibility tool selected.

I followed the documentation on creating the Landscape Hole Material, and applied it as in the instructions… but no luck.

In some of the answers there are references to some kind of problem with this, is that still an issue, as the answers seems to be about a year old?

Anyone know if there is an alternate way of creating the hole?