If you have reopened or duplicated a project in the Projects tab for reuse with a new client, you will need to overwrite the existing index to update the portrait set.
To do so, simply click on the Import CSV button to bring in a new index and image set. The current set will be replaced.
Note: if you have accidentally opened a project but need to save changes as a copy, so as to preserve the original file, toggle directly from the Index or Editor to the Projects tab.
Choose Save As New Project to make a different version under a new name.