Importing the office file attachments into imported page content is not working (anymore)

How to reproduce:

• prepare a file to import with a column referencing an office file in a column
• map the column on the doc attachments column at mapping time
• configure, manually in object mode, in the BatchImportClass, to upload files and import files in the page content
• configure also the folder with files on the BatchImportClass in object mode
• make sure the office server is configured
• run the import

Expected result:

• the file from the attachments column is:
  • uploaded as an attachment to the imported page
  • its content is imported as content in the page (through the office importer)

Actual result:

• the file from the attachments column is:
  • uploaded as an attachment to the imported page
  • its content is not imported as content in the page. The imported page content is empty.

If, at this point, a new import is ran with the same parameters but without deleting the imported page with 'update' deduplication option, the content is now set properly.