3D Invigorator and shadows - AE lights vs Invigorator lights.

I have a 3D model loaded into Invigorator, and I want it to cast shadows. Obviously the way to do it is create a shadow catcher plane in Invigorator. That works fine, and when I case a light onto the model, I see the shadows as I expect, but I've noticed something, at least when using After Effects lights: Although the model does cast shadows correctly onto the shadow catcher plane, I've noticed that the model doesn't cast shadows onto itself. It does do this when I use Invigorator lights, but not when I use AE lights. Am I doing something wrong or is this a limitation of using AE lights instead of Invigorator ones?