How to compare the positions of points on two different geometries in geometry nodes!! :(

I've been using geometry nodes for quite some time now. I've done a variety of things with it.

I feel like there must be a glitch with blender 4.2 because what I'm trying to do is so simple.

I have a mesh of some points with edges in between them.

I've used a sample index node to get the position of each point.

I have a high poly geometry that is created through the manipulation of the original geometry. I've used a sample index node to get the positions of those vertices.

I've used a compare node set to equal and vector to compare the positions. I've connected that to the selection of a separate geometry node. The high poly geometry goes into the geometry input of the separate geometry node.

This should only output the areas that are within a given radius of the points from the original geometry.

What I would greatly appreciate is someone telling me why this is not working.

It's just being really weird, almost separating by ONE of the original points but not even doing that properly. I've changed with the epsilon, changed the compare type to length, average, all the others. I have no idea why it won't work.

Does it have something to do with the fact that I created the high poly geometry from the original geometry? And if so, how do I make it work, because I need to use the original geometry to make the high poly geometry.

Thanks if you can help.