I just tried again and I notice auto-scroll does not work if I have a note selected. Is this by design?
yes, this is by design. Usually you select a blob because you wish to edit it. That's why Melodyne keeps the focus on the selected blob and auto-scroll is temporarily disabled. I understand that this is not what you want after
you have already done your edits. But in these cases, a simple click in the background to unselect any blobs and to re-enable auto-scrolling does not really hurt, does it?