Hi, thank you for the interest!
I prepared a new project with a demo level (which also shows this can be reproduced in new projects). Let me know if you can open it correctly. Unique Download Link | WeTransfer
The link will expire in 7 days, btw.
I made an interesting discovery too. We are not seing shadows, as I thought at first, the black areas are black because we are seing through the mess to a shadowed area. What I mean is, we are not seeing an occlussion, we are seing a refraction. We see through the geometry that is about to be intersected, but light does not go through the geometry. You´ll be able to see it clearly in the file I provided, where you´ll see geometries being intersected (or about to be intersected) with others. Play around with the different lights I set up.