Are your normals inverted? I’d say so because I can see the legs of the chair through the seat. In 3D models which are not shaded “two sided”, there is one side considered the surface, and the other side considered invisible. That is why, with inverted normals on a model like this, you can look through a surface and see the inside of the model on a surface behind it. In such case, the normals need to be recalculated so that the “outside” surface of a mesh is not invisible, but the inside.
Blender has some options to visualize normals as arrows pointing out from faces on the viewport so you can check them. If they point inwards, they are inverted. Invalid for your model.
Otherwise, an inverted normal shows dark where a good normal shows a lighter tint in Blender.
CTRL SHIFT N is used in Blender’s edit mode to recalculate normals on selected verts but depending on a model you get either a good or wrong result. Look up “blender invert normals” on the webs and there is a lot of info on it.
If it looks fine in Blender, check that the content importer does not mess up normals.
If none of the above, could still be a material (shader) issue I suppose.