Tried to migrate Confluence server to cloud but after migration noticed that some images are broken.

First tried to export the space and import it on the cloud. Also tried to use the migration tools on server to copy data directly to cloud but the same issue.
The affected images are displayed correctly on the server.
Tried to compare the failed attachments and the one which got migrated properly but cannot see any obvious reason.
Here is the link from the server which failed

Here is one which was successfully migrated

My server version is: 6.15.4