[Newbie] Why does my ShaderGraphMaterial appear distorted?

Disclaimer: I am new to all things 3D. There could be a variety of things wrong with what I'm doing that are not unique to RealityKit. Any domain info would be appreciated.

So, I'm following, what I think are, the recommended steps to import a shader-node material from reality composer pro and apply it to another modelEntity.

I do the following:

guard let entity = try? Entity.load(named: "Materials", in: RealityKitContent.realityKitContentBundle) else { return model }

let materialEntity = entity.findEntity(named: "materialModel") as? ModelEntity

guard let materialEntity else { return model }

I then configure a property on it like so:

guard var material = materialEntity.model?.materials[0] as? ShaderGraphMaterial else { return model }

try coreMaterial.setParameter(name: "BaseColor", value: .color(matModel.matCoreUIColor))

I then apply it.

This is what my texture looks like in RealityComposer:

I notice that my rendered object has distortions in the actual RealityView. Note the diagonal lines that appear "Stretched".

What could be doing this? I thought Node Shaders were supposed to be more resilient to distortions like this? I'm not sure if I've got a bug or if I'm using it wrong.

FWIW, this is a shader based on apple's felt material shader. My graph looks like this:

Thanks