GhPython Boolean Operation: is this a bug?

Hi guys,

So I was trying to join two Breps together with the BooleanUnion in Ghpython. However, it seems like in my case, the BooleanUnion performs more like the BooleanIntersection, while the BooleanIntersection performs like the BooleanUnion. I’m not sure whether this is a bug or something else…

Please check the attached screenshot.

When using the BooleanIntersection :

When using the BooleanUnion:

Any thoughts?

-zeming

could you please share the GH file with internalized geometries?