*Officially*
It seems its "partly working". "Before, it wasn't actually occluding even when it seemed to be, upon fixing that, it seems its the other way round now". It's being looked into.
In testing it looks like existing models (for the most part) are occluding, where new ones may or may not.. so its an odd one, but is being looked at.
*Note, Visibility > Occluders is currently not enabled and when Viewability is set to 'Occluder_Only' under asset properties, the entire asset disappears.
Right, forgot about that, I use imported occluders and haven't tested with the "occluder_only" meshes in some time.
Yeah, your asset looks fine

Max would likely provide the same result.