Resolved Can't hook node to Vertex Position input

I'm trying to make a hologram 'glitch' effect where a ring of vertexes pulse up and down the object

I'm unable to connect to any of the Vertex ports with the current method I am using and was wondering why? Am I going about this the wrong way?

If I replace the Sample Texture w/ a Simple Noise node it is able to connect to the Vertex inputs

 

If you are working with the vertex position output your calculation are run at the vertex stage of the shader.
Not all nodes are available at that time.
You can use Sample Texture 2D LOD Node in place of your normal Sample Texture 2D Node.
That should fix the issue.

https://docs.unity3d.com/Packages/com.unity.shadergraph@6.9/manual/Sample-Texture-2D-LOD-Node.html

 

That fixed it, thank you!