I've noticed that sales of paperbacks, sold through KDP, don't do anything for author rank. I sold a couple of paperbacks about three or four days ago and saw no bump in the line at AC. Being a small fish in a very large ocean, whenever I sell an ebook, the graph at AC looks like a rocket shooting for the moon. But, selling two paperbacks in one day and the graph still looks like a ski jump at the Winter Olympics. I noticed this last month when I sold two other paperbacks in one day, just before Christmas.
Interesting that KDP printed paperbacks don't seem to count toward your author ranking.
If so, that's probably a glitch. It's hard to believe Amazon would give KDP Print paperbacks less weight than it gave the Createspace ones. Anyway, Author Central tracks ebooks, paper, and audio, so you'd expect that all three would factor into author ranking.
I'm not in a good position to test right now. I checked back, and all the recent paperback sales happened when there were also ebook sales.
Of course, author rank is also affected by what other people are doing. I've never seen a zero uptick from a book sale--I'm prawny, too--but it might be that there was a lot of activity. You got a small surge, but it disappeared quickly. Because Author Central author rankings don't update very well in real time, it's possible to miss a small uptick because it may have disappeared before the next update. (When I used to use one of those services that provided hourly updates, it always showed a lot more ups and downs on individual titles than Amazon's once-a-day kind of reporting does.