My only question would be if you have continued to practice jumping. This is probably a big part.
I haven't noticed my vertical going up much despite significant increases in speed (from 0 through 400m), strength (squat/pc/etc.), medball/shot (well over 60ft with the 4k shot and over 52 with the 12lb), and standing long jump. I also do not practice my vertical, which is probably part, along with having ankles/calves like bricks. I really don't care that much about my vertical, just something interesting.