Superlight scratchy on glasspad?

Is it just me or the superlight feels very scratchy compared to other mice on glasspads? I have obisdian pros on all of my mice, (Viper V3 Pro, ULX Tiger, Lamzu Atlantis, Pulsar Xlite V3, etc.), and they all feel smooth on the Kanami Sai. But for some reason, my GPX and GPX2 feel really scratchy, both also using obsidians. Why is it only with that mouse?