The old issue view used to render every attachment, regardless of if the user had permission to see a restricted comment which contained an attachment. But in the new issue view, the attachment panel will show only those attachments that the user has permission to. So In other words, if an attachment was uploaded in a restricted comment and is not visible to a user, attachments with those comments would not be visible in the new issue view to that user.

It is desired to have all the attachments visible to a user who can view the issue(just like the old issue view).