V9 read email not remove from Unread after changing folder

After an email is read and has a tag it is not removed from Unread folder. If the email does not have a tag it is removed from Unread after being read or marked as read.

The read message is displayed in the Unread folder until you move to another folder.

That is to prevent a cascade effect of messages being automatically marked as read after x seconds and then being removed from the view without you ever having read them.