Hi,
In order to record the sales the Google analytics plugin has to display javascript code in a page that is displayed on a browser.
So when you confirm an order in the backend, unless you display another page after do that, the sale won't be taken into account as the plugin doesn't have the possibility to add that javascript with the status change procedure.
So make sure that when an order status is changed to confirmed, you display another page on your backend and it will take the sale into account on that page automatically.