To recreate: 1 - Export some records form Koha 2 - Strip all the subject fields 3 - Stage for import - Set matching rule on 999 or isbn, whatever works - Set action when matching record found to ignore 4 - View the batch and see the matches 5 - Click the diff view 6 - It shows the imported record with subject stripped 7 - It shows the subject fields in the existing record crossed out 8 - This makes it look like the import will remove fields 9 - Import the batch 10 - Confirm the records are still complete, subject not removed