My Envoy did the same thing, after the 3rd dive it was breathing hard, took it to one dealer (because I got it from scubatoys and I had a dive on saturday, I didn't want to ship it back), he couldn't figure it out.
Took it to another dealer (at the last moment.. friday evening), after 2 seconds he figured out that the IP dropped a bit, fixed it, in 5 minutes I was out and a perfect regulator in my hands, I asked him if he can fine tune it, fully open will freeflow a bubble a second, he got it right.
During that whole story, I contacted Zeagle, Jim Fox was REALLY helpful and guided me how to check it by myself, he did say that if I try to do any fine tuning myself it will void the warranty and even offered I'll ship it to the factory and their techies will fine tune it for me.
Guess which regulator I'm considering for my next purchase?
Apparently it needs a bit of time to be broken in...
Oh, even on devil's ear, where the flow was really hard, I've heard a hissing from my reg, closed the knob a bit and the hissing is gone.
I like my Zeagle..