Hi there! 
U know about this situation, there is no ability to clone attachments to another project in Jira Automation, just only in Automation Service Desk. There is a link of this task https://codebarrel.atlassian.net/browse/AUT-1030 but nothing was changed a few years for Cloud, its so sad. Can you increase the importance of the task, since it makes the automation process quite difficult? Thanks a lot!