Shiny objects appear black

I've created this big game, imported a bunch of assets (from both the asset packages and the unity asset store) and now I realise that my shaders are messed up. I reckon it's because it's some kind of light map thing but I have no idea how to edit it or to confirm that it is.

To demonstrate this, I've created a new scene in my project and created an object called 'Shiny'. I can instantly see the default material is a bit wonky and the shininess on materials don't work.

Is there any way to resolve this problem? Thank you.