Studious
Just installed X2 recently and experienced a V-Vocal bug playing back the sample project. All the V-Vocal clips either do not play at all, or they play way out of pitch (chipmunk).
When there is no sound, the V-Vocal editor is empty (no waveform).
When it's chipmunk, everything looks normal.
Make sure you haven't inadvertently muted the track (or solo'd another track) before you create the V-Vocal clip. Also, make sure you change the formant control to zero to avoid the chipmunk. If both of these are OK, maybe you are seeing a different issue.
In the case of the particular project I originally referenced the V-Vocal clip showed the waveform, but would not play. This was an older project opened in X2. I haven't seen this behavior in a project created from scratch in X2, or even in other older projects.
What I have seen recently is a case where V-Vocal didn't mute the underlying clip in a lane, and I could hear the underlying clip as well as the tuned clip- THEN, when I muted the underlying clip manually the tuned clip became extremely distorted and I could find no way to make it better (except starting over with Melodyne.) Have not been able to reproduce in any other project, but have pretty much given up on V-Vocal even for small changes in favor of Melodyne. I'll give it a try again after the next update.
John