Audio preview not working in VariAudio

I don’t know if I have some setting wrong but anyway the AUDIO PREVIEW button IS enabled but I cannot hear anything when clicking on a note segment, say, in a Vocal track which has been analyzed and when actually dragging the note events vertically to new position (note).

It worked fine in C6.5 so please tell me if this is a bug or if I’m having something falsibly set in Preferences etc.