I started a lab challenge with static NPC, started 2 levels down from the surface. When I took the quest from the NPC (get software from my computer), he revealed the map around the target area… 2 levels down from the surface (most of it is “solid rock”). Conveniently, I can see the house with the red * right on the edge of the mapped surface area… anyway, bug! FYI.
I’m playing vanilla 0.C with experimental Z-level mod (that it comes with).