Thanks for posting this, I’ve spent a couple of hours trying to debug my lighting setup because I’m having a similar issue. My character is on Lighting channel 0 and is lit with lights in Channel 0. I want to have special control over my character’s shadow and I have a dedicated shadow-casting mesh that’s hidden in game (with hidden shadows on). The shadow-casting mesh is lit with a shadow-casting light on Lighting channel 1. My background is set to receive shadows from both channels.
However, this doesn’t work with the current Lumen/Raytracing lights.