Hello hz211,
For now, there's no exact time when will be the Starling bank available in QuickBooks. It has been raised to our banking engineers and they're aware of it. I can't provide a specific time-frame yet. Rest assured, they're working to make this bank available in QuickBooks.
Usually, the duplicate transaction happens when the bank was manually updated. At the same time, the bank also do an automatic download. If you've properly posted all those transactions, you always have the option to disconnect the bank.
Fill me in if you have additional questions with QuickBooks. I'm just around.
