If you delete individual items from Dividends, that will not affect the items entered as Interest.
Once you import data and it's entered in different areas of TurboTax, the data will remain in the areas entered.
In TurboTax Desktop, you can delete imported items as follows: Open your return. From the TurboTax File menu, select Remove Imported Data. Select the item(s) you want to remove and follow the instructions.
See this help article for more information about issues with importing data.