Area Lights casting Specular regardless of material specular value

The rectangle lights ignore the specular value of lit materials and will apply a specular highlight to them regardless of the value. you can compare the result against a standard point light and you will not see a specular highlight for those.

Create an Empty Scene

Create a new material and connect a constant 0 value to Base Color, Metallic,Specular, Roughness,Anisotropy,Emissive Color.

Add sphere mesh to scene and apply material.

Add a rectangle light.

Observe specular reflection on sphere surface.