After migration using JCMA attachment previews don't work, works on refresh

Issue Summary

This is reproducible on Data Center: No - intermittent issue

Steps to Reproduce

1. Migrate projects using JCMA
2. View Jira Issues in the cloud site which have attachments 
3. The attachments don't display automatically but instead show preview unavailable
4. Refresh the page 
5. The attachment preview displays as expected
6. The attachments are always accessible in the Jira Issue and were migrated okay - this affects only the attachment preview

Expected Results

The attachment preview should work automatically post-migration without any refresh required

Actual Results

The attachment preview doesn't display from initial Jira Issue viewing. You have to refresh the page to get the preview to work. 

Workaround

The workaround is to refresh the page. Then the attachment preview will display as expected. 

Please contact Migrations Support if you want this fixed across the site.