I see your tessellation multiplier at 0, it needs to be a positive integer. Also your heightmap seems to be almost a solid color, so you wouldn’t expect to see much relative displacement. Try it with the cobblestone textures I had in my screenshot to see if it works at all in a material, or it’s something else in your settings.
In regards to not moving the mesh, you are using a map to adjust the physical positions of the mesh-vertices; it’s expected to move somewhat. Larger values will move it more.