Attachments not loading after Confluence migration

Issue Summary

Attachments are failing to display for migrated Confluence space. Thumbnails are not loading on Confluence pages but the attachments will load from the 'Attachments' page fine.

Steps to Reproduce

1. Migrate Confluence space from Server to Cloud using Confluence Cloud Migration Assistant
2. View migrated Confluence space in Cloud instance

Expected Results

Page loads properly displaying all attachments

Actual Results

Some attachments fail to be displayed even though they are present on the Cloud instance
Logs show:

2020-04-27 18:08:35.307	WARN	com.atlassian.confluence.servlet.download.RedirectToFileStoreDownload	Failed to obtain thumbnail for attachment 298871 (processing status: FAILED). Sending redirect to the original image.

Workaround

• You can access and view the attachments by clicking on '...' at the top right and selecting 'Attachments' to load a list of all attachments on the page.
  OR
• If there are multiple pages affected, please contact Atlassian Migration Support team and ask to apply a workaround for this issue, the migration support team can apply this workaround on your cloud site.