I'm trying to export a simple plane with a set of PBR textures from blender 2.8 to godot, here how's shown in blender

and here how's show in godot
I'm ok with a little difference, after all every program is different, but this is unnaceptable.
I know it's not the exporter, because another viewers of gltf files load it correctly, like this on the web

I even tried the same test HDR background for illumination, and doesn't seem to make a lot of difference, this is the shaders that I'm using in blender

the texture set is this one:
https://cc0textures.com/view?id=Tiles058
has color, normals, metallic, roughness, like it should.
So, what I'm doing wrong?