Well 1st of all welcome! Second of all; do you know if the GD came shave ready? (I'm assuming no)...What could be happening here is that the bevel may need to be set. Setting the bevel is definitely the most important step in any honing regimen, as it establishes the geometry of the edge. What ends up happening if you don't set the bevel is you end up just polishing a dull edge. This is what I ran into when I first started honing (just a few weeks ago!!), so I went and got myself a 1k Bevel-Setter. It really makes all the difference in the world!!
Now it IS possible to set a bevel off of just the Norton 4k, it just takes a little more effort (and slurry). I am, however, just a newb myself, and I'm sure some of the more "veteran" honers will chime in here!! :)