Freeing up space · Emergency Space
Why won't Storage Studio relocate a folder that was already moved?
Short answer: A moved folder is now a set of links to your fast drive; moving it again would copy links over the real files. Storage Studio refuses only when everything is already linked; any real content still moves normally.
Because what's left in a moved folder's place is a set of links pointing at your fast drive, and moving that again would have meant copying the links over the real files. Storage Studio checks for this before it starts.
The check is deliberately one-sided: if there's any real content still in the folder, the move goes ahead as normal. It only refuses when everything it finds is already a link to the same destination. To manage a moved folder, use the Relocated panel — see What is the Relocated panel?