When using the the principled BSDF shader with any amount of sss the diffuse passes are completely black. It seems the sss passes inherit the diffuse pass information. The node tree is just the shader and the output node.
If I turn the sss down to 0, the diffuse passes work again.
When instead using a regular diffuse shader, mixed with an sss shader, everything works as expected. Diffuse passes included.
Is this a known issue, intended behaviour of the Principled BSDF shader or just me doing something wrong?
I'm using Blender 2.81