ilv2hunt,
First, welcome to the forum. Lots of good info to be found here. Lots of good people as well...
I second what FloridaCCW says. Speer Gold Dots seem a trouble-free round. Federal Hydra-Shok and Winchester Silvertip also seem to work well in the R9, judging by past threads on carry ammo. Some members swear by Remington Golden Sabers in 147 grain.
Hornady Critical Defense has caused issues for many Rohrbaugh forum members. Unlike Speer, Winchester and Remington (who manufacture their own primers), Hornady buys its primers. Over the past couple of years, ammo components have been in short supply and the small ammo companies like Hornady have had to take whatever primers they could get. I've shot up a couple of boxes of Hornady C.S. in my R9s with no issues, but I still don't trust them enough to carry - yet.
To answer your question directly, I'd wager it's the ammo not the gun. Still, you need to shoot more brands of premium (expensive!) ammo thru your R9, then stick with the brand that works best in YOUR GUN!
Steve