The Reflectance property usually just reflects the skybox so it only works on day time. However, if the time is night, the reflection is not going to appear at all and will usually just look like black part.
This is the reflective part at day time.
This is the reflective part at night time.
FYI: I want every part to be reflective
I haven’t had experience in this area, but maybe you could try changing the skybox when it is night to something else more reflective.
You need there to be a light source for your parts to be reflective, however, you could use different materials like granite or marble and turn the reflectance up in the properties tab. Hope this helps.
