It can be problematic deleting/correcting one transaction of imported data. However, If you delete your import, then re-import answering the question 'did you purchase all of the xxx?' with NO, TurboTax will let you address each transaction separately, so you can correct/delete individual ones.
You could then make two manual entries for that transaction, as you suggested.
Here's more info on Edit or Delete Imported Data.
@patel21
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