The Principled BSDF shader doesn't bake the Diffuse (Base Color) properly when the metallic is not zero. This workaround is for using a Custom Pass with the property set to Base Color. Did some testing and is working for me when baking out PBR work flow:
Base Color (custom pass with this workaround)
Metallic (custom pass)
Roughness
Normal
The Principled BSDF shader doesn't bake the Diffuse (Base Color) properly when the metallic is not zero. This workaround is for using a Custom Pass with the property set to Base Color. Did some testing and is working for me when baking out PBR work flow:
Base Color (custom pass with this workaround) Metallic (custom pass) Roughness Normal