Files and images are not transferring when duplicating a post

I have a post on my main site and I am trying to duplicate it on to another multisite. Everything moves except the “file” and “image” fields. Both are setup with a return value of “file URL”. The files don’t seem to move at all and the duplicated post just shows the field as “No File Selected”. Let me know any information I can provide to help resolve this issue and thanks for any help you can provide.