Currently, attachment preview links such as those in this format are not corrected via the "Update product links" (https://support.atlassian.com/migration/docs/update-product-links/) or legacy link fixing script (https://confluence.atlassian.com/confkb/after-a-successful-server-to-cloud-migration-url-links-are-broken-in-the-new-cloud-instance-1077781093.html).

• <SourceBaseURL>/display/TM/Test+Attachment?preview=/1966086/1966085/Test2.txt
  1966086 is a contentID (contenttype = page)
  1966085 is a contentID (contenttype = attachment)

Instead, both these methods only change the baseURL, without making changes to the contentID part of the URL. After running linkfix, the new link looks like these:

• https://testsite.atlassian.net/wiki/display/TM/Test+Attachment?preview=/1966086/1966085/Test2.txt
  This is incorrect and will not load the preview because the contentID changes after migration to Cloud.

Either, the link fix tool should change the URL to a correct one (map new contentID), or not make any change for this URL at all. Else, in the current state where it changes just the baseURL, it results in a link that does not load the preview, but gives the impression that the link is fixed because the baseURL is changed.