Thanks for the reply Aleksandar.
So basically the field "Quantity Invoiced" in the Purchase Blanket Order item line must be the same as the "Quantity" and "Quantity Received" item line in order for NAV to see the status of a Purchase Blanket Order to be "complete'' (so to speak)?
I tried the above suggestion and used the "Delete Invoiced Blanket Purchase Orders", but the Blanket Purchase Order was still visible in NAV rtc.