Why does my black african knife fish hide all day?

I bought a black african knife fish about almost 2 weeks ago and he hides all day and when I shut off the light he comes out. Is that normal?
He comes out and hides in the plants and stuff sometimes
But the thing is that he never eats. When I feed my fish he comes out but he does not go to the top and get the food. he digs in the rocks. And I do have a tunnel he hides in.

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