In my quest to break things in the game, I discovered a quirk with building in caves. I’m lining walls in a cave 4 blocks tall with the flooring already built as a separate build. The bottom two layers of the walls went smoothly but they attempt to build scaffolding as they proceed. The result is an inability to finish the wall because the scaffolding can’t be finished above the second layer. The hearthling tendency to build while standing on the layer below means they can’t complete a cave build without 3 blocks of headroom above. Including a screenshot
Edit: the walls are built with the slab tool
i’m currently using the experimental AI and pathfinder (both are great, btw) so I’m not sure if that factors into the cave building