I had no audio in the instant replays I captured and the microphone audio was also sputtering/stuttering. I have managed to fix this by disabling every audio capture device in windows sounds (screens, audio cards, etc).
This could have had an easier fix if Relive would have allowed me to select my own audio capture device manually. I can do this for a microphone. Then why can I not do this for my audio capture device and have to disable everything else?
Hope this will help some of the people with the same issues and hope AMD will look into this.