Black shadows using HDRP/Lit shader

I have created a new HDRP project which has the workbench scene in it. I set about creating some materials for my project, but I have a shadow problem I can't seem to solve.

I created a plane, and a new material (seen in image below). I set it up exactly the same as the floor material currently in the scene, but the shadows are black on my new material. If I drop the floor material from the scene onto the plane, it's fine, the shadow works correctly. But put my new material back on, and it doesn't. I can't find anything about this. Any help would be greatly appreciated.

 

same problem here

 

I got the exact same problem, in a forest it looks really bad. Shadows should be transparent so you can see what's in the shade, not pitch black. Is this a bug that will be fixed in the future?