MS Access Duplicating records does not create a unique AutoNumber for ID column

Hi. I am using the following SQL in an Access Query to duplicate rows for a certain TransactionID. It works fine but for some reason the new records have the same number
as the original records for the ID column, which is an AutoNumber column. I'm not sure how this is possible as I would expect unique numbers to be generated.


INSERT INTO Transactions
SELECT *
FROM Transactions
WHERE TransactionID=17330;