have you perhaps tried the Melodyne editor Trial since you installed Melodyne essential, and played with its Pitch Background
options? If so, please try trashing the Melodyne preferences file com.celemony.Melodyne singletrack.plist
(with a capital M!) in Users/<your name>/Library/Preferences
. Does this already make a difference?
If this doesn’t help, please contact our support team
. They might need to ask you for further info.