Duplicates upon importing PDF2Anki deck onto Anki

After downloading my AI-generated deck from PDF2Anki and importing to Anki, it says that "11 new notes have been imported" and "660⁩ notes were not imported, because their notetype has changed, and '⁨Merge notetypes⁩' was not enabled." I only intended to have 150 total flashcards to import (and I specified this on the custom instructions). In my other decks I've imported, I'm getting 600+ cards, many of which are duplicates, which take forever to sift through and delete. Need help with this please. Thank you.