New 999 $s created when exported file is re-imported to update an instance

Overview: When a MARC file is exported from FOLIO and then re-imported to update instances, a new 999 $s is created, but it shouldn't be.

Current workaround: none

Steps to Reproduce:

1. Log into FOLIO-snapshot-load as diku_admin
2. Import the attached file to create instances, using the secret button
3. Go to Inventory and do a Query search for Source=MARC. If no one else has imported today, the search should return only 5 records
4. Go to Actions/Save instances UUIDs. A csv will download with Instance UUIDs
5. Go to the Data export app
6. Upload the UUID file you just exported and use the Default job profile to export the MARC records from FOLIO.
7. The file name will appear at the top of the export log. Click the file name to download it to your desktop
8. View the exported MARC records, especially noting the 999 ff in the records.
9. Create a new job profile in Settings/Data import
   • Field mapping profile
     • Name: Update instance
     • Incoming record: MARC
     • FOLIO record: Instance
     • Cataloged date: ###TODAY###
     • Instance status: "Cataloged"
   • Action profile
     • Name: Update instance
     • Action: Replace
     • FOLIO record: Instance
     • And link the field mapping profile to it
   • Match profile
     • Name: 001 to Instance HRID
     • Incoming record type: MARC Bib
     • FOLIO record type: Instance
     • MARC field: 001
     • Matches exactly
     • Instance field: Instance HRID
   • Job profile
     • Name: Update instance
     • Incoming record type: MARC
     • Add match profile: 001 to Instance HRID
     • If matched, add action profile: Update Instance
10. Import the exported file, using the new job profile you just created
11. Once imported, Check Inventory to confirm that the catalog date and Instance status were updated
12. Click View source to review the 999 ff fields of the updated records

Expected Results: The 999 ff that was created when the original file was imported should remain the same. No new SRS UUID is assigned

Actual Results: A new $s SRS UUID is assigned, and the existing $i Instance UUID is repeated

Additional Information: See attached video (2 parts) and sample file.

NOTE: In MODSOURMAN-333, we're going to remove any existing 999 ff field when creating new SRS and Instances in FOLIO. Should we maybe do the same when updating, and then add the existing 999 ff to the updated MARC SRS?