Metallic Object Totally Black and Doesn't Respond to light

Hi there, I have been working on the new lighting system for a few days and face a lot of problems, but this one make me really hard to understand and solve.

Well, I am trying to make this ground in the picture to be like a metal and I want it to reflect the cube, so I add a Reflection Probe and a directional light and the cube, and then I set the Metallic of ground to a high value, and then it become dark,which shows in the picture.

And what's more strange is that all the scene between baked and realtime is different, the picture here is use bake mode and if I turn it to realtime, it just give me a scene like no lighting.

If I reduce the Metallic of the ground it start to become lighter but do not have enough reflection.

I really can't figure out what happen, any one please help me, I 'm about to break.

 

And this is the baked scene, it still really dark................
I have checked Quality Setting every thing is correct, but it still doesn't work.

 

What are you reflecting with your probe? A fully metallic surface is only showing the color of the reflection tinted by your material's base color...so unless have assigned a cubemap to the reflection probe and/or assigned skybox as your reflection source and set the probe to reflect your skybox, you won't see much.

 

Yes my reflecting probe doesn't reflecting the skybox, but I have a light here, why it don't reflect the light and the cube? Well I just feel it not like a metal it just like a blackhole..

And If I let them reflect the sky, it always have a very annoying shiny circle, maybe it is the reflection of the sun, so that is way I use reflection probe to avoid it.

Just don't understand why the little point light is not reflecting, it have a clear effect during baking and after bake it just gone.