There was no setting change between the two renders. I also can’t pin point when it switches between soft and hard shadows. Happening arbitrarily it seems.
Does my amorphous shape somehow interfere with how sun light is cast?
This isn’t an issue with legacy rhino legacy renderer
The geometry is from a grasshopper script, specifically the preview component that can push meshes to be rendered without adding it to the rhino objects table.
You may have to click render a few times or fiddle those GH sliders to get the “lucky” shot.