This is generally just a bump, i do not no nor have i played with unity though i do want to come in an say one thing that could help idk if it will. or you can also update the thread with the solution of what it was. But i've run into some funny "shader" issues where this black & blue look comes into play with highlights…
Thanks. Well, it sounds to me like "fuck around and find out" kind of problem lol. If I'm mucking around with shaders, but don't understand the math that I'm actually implementing, then I can get all sorts of wonky visual behavior. The problem here is probably something goofy in your node chain.