The Dedupe feature might say "Looking Good" despite duplication in rows 50 and 51 due to how it identifies duplicates. Dedupe works based on exact string matches and is case-sensitive. It's possible that there are slight differences between the rows, such as extra whitespace or capitalization, that the system doesn't recognize as duplicates.
To address this, you can try manually deduping the column:
1. Right-click the column containing the duplicates
2. Select "Dedupe" from the menu
3. Choose "Delete Duplicate Row"
If you need more assistance, you can request human help by clicking on "Talk to a person" in the chat.