Unless you have pages of 1099-B transactions, it is probably easier to manually enter your 1099-INT's. If you can't select them individually on the import site, the second import often overwrites the first one.
To add them manually, click on 'Add Investments' and then 'Skip Import' from the import page. Select the Bank Interest icon on the next page, and on the next page, enter your 1099-INT.
@barbagg