LWRP confusing / black materials

Experimenting with LWRP and I don’t get the material setup!
Used the 2019 template, made a new scene and setup lighting for realtime only.
Create a material (LWRP, specular) and made it white - looks ok
Put the specularity to white - material goes dark grey or black depending on smoothness level?!

why does this happen and how do you get simple colored materials to look similar to built-in?

It anyone using LWRP? It’s hard to understand it when just adding specular seems to make a material turn to black

You might want to try the Graphics Experimental Forums, they have more LWRP stuff.