Uncalculated shading objects in Ladybug radiation analysis

I’m trying to run a fairly straight-forward radiation analysis on a set of urban tree canopy models using the Ladybug plug-in.

However, I’m finding that some of the tree geometries I’ve selected as shading objects do not get included in the output color mesh.

ShadowExample_01

This bug seems to occur inconsistently, as demonstrated by the tree on the bottom left. This object does not cast a shadow in the previous screenshot, but is shown to cast a shadow in the following example - even though these objects represent the same tree (they have the same form, and were produced based on the same tree data).

ShadowExample_02

Has anyone run into similar challenges with the radiation analysis component skipping over shading objects?
Is there a known solution to this bug?