SpotLight doesn't work properly with PBR materials

If a SpotLight is directed to a model with PBR material the light spot doesn't look correct.

See the attached image.

To reproduce:

1) open "Light example"

2) add to each Model with source: "#Rectangle" this material:

PrincipledMaterial
{
    baseColor: "#999944"
    metalness: 0.9
    roughness: 0.2
}

Another problem is the intersection line of 2 spotlights, light should be twice as intensive there but instead it falls (see example3 image). This problem is reproducible with DefaultMaterial.