Hole series doesn't work with part that has varied thickness

I am attempting to create a hole series in my assy to use for bolt connectors in a study I am trying to run. The problem I have come up against is that the hole series doesn't want to create the feature in a part that has a varied thickness. See screenshot below. I am trying to put either a counter bore or just a plain clearance hole starting at the green highlighted surface through the bottom of the part. Can't seem to get it to do it. It will create the tapped hole in the flat plate that is bolted to the bottom of this part. Is there a workaround for this or is it a limitation of the feature? I have tried adding a hole wizard to this part and use existing hole with the series, but it ends up putting a hole along the highlighted surface rather than a series of holes perpendicular to it.

SolidworksAssemblies