Updating File Names via CSV Import

-- HikaShop version -- : 4.3.0
-- Joomla version -- : 3.9.21
-- PHP version -- : 7.2.0
-- Browser(s) name and version -- : Chrome

Hi Team,

I've been able to import & associate PDF files via CSV using the column headers "files_name" and "files".
This worked well for the initial import and the 900+ products have the correct file name titles and files.

I now need to change the file names and files associated for each of these products. When I modify the file names & paths in the CSV within the appropriate columns "files_name" and "files", and then re-import the updated CSV with the new values, the import seems to work correctly with no error messages, but the fields are not updating in the backend (they retain the initial file names and paths).

What am I doing wrong?

Thank you

Mike