Can't hear individual note pitch changes in VariAudio

When editing vocals in the sample editor, I can’t hear an individual notes’ pitch in VariAudio when I drag them up or down to adjust the pitch. The Solo monitoring in the Editor is working fine and just plays the Editor window on its own; it’s just when I drag a note to change its pitch that I can no longer hear that note being dragged.

Control Room monitoring is set to sound card outputs 1 and 2 and everything else is fine.

It used to work OK - this function may have been lost when I recently upgraded to Pro 12.