Sometimes files don't finish processing, and it's not clear why

Overview: Files get stuck sometimes

Steps to Reproduce:

1. Cannot reproduce consistently, so I don't know exactly what to tell you to do - see attached video
2. Log into FOLIO-snapshot-load as diku_admin
3. Import a file
4. Check data import landing page to be sure the file finished importing and is listed in the log

Expected Results: File should finish importing and be listed in the log

Actual Results: Sometimes they get stuck and show in the "Running" area forever

Additional Information: See attached video

For this particular one (MARC file is attached), I was creating instances, holdings, and items. In the item record, I mapped the barcode from 949$a. After it got stuck, I re-imported the file. Item records were not created. When I checked Inventory, I discovered the original file actually created Instances, Holdings, and Items - just never showed as complete on the Data Import landing page. Since the barcodes were duplicates when I re-imported the file, that caused the item record creation to fail (but instances and holdings were created).