Substrate - Feedback Thread

Hi, question about substrate with Lumen.
I found that lumen did some effect on SSS backlit, but when substrate on, this effect is gone.
Here I did a 5.3 test scene with substrate turn off, defaulit lit material, putting a point light on the back. I really like to get the light passing through ears.


But when I turn on substrate, the light are “block”, nothing changed whether I turn on/off lumen.
Anyway to fix that?