You got the order wrong, the long sleeve goes on the top hat BEFORE the ring with the grooves cut into it. The ring then slides onto the tophat and fills the gap between the tophat and the sleeve. The octagonal ring goes onto the threads of the tophat (AKA where the tophat crews onto the back cap).
Don't ever have your reg turned out (counter-clockwise) all the way, it can cause leaks all throughout your gun. The HPR should never need to be more than 3-5 turns out.
You clearly need more pressure in your tank in order to actually test the eigenring.