Win 10 app doesn't notify of mail in additional mailboxes
In the Win 10 mail app. I have a Primary account plus have added two additional yahoo account mailboxes (called Work and Play), and they are syncing properly. When I receive new mail in the 'Primary' account I get a Windows Notification as expected. But when I receive new mail in one of the additional accounts ('Work' or 'Play') I do not get a Windows Notification even though the account selector in the left pane shows the unread messages counters properly.
This seems like a bug. I would expect to receive notification of a new message in any linked and synced mailbox.
To clarify, this is in the Yahoo Mail app installed in Win-10, not the Microsoft mail app.