Updating SharePoint file metadata with Set-PnPListItem requires the correct UpdateType. Use SystemUpdate for author and retention label changes, and UpdateOverwriteVersion when updating the editor. When to use SystemUpdate SystemUpdate updates list item metadata without creating a new version or changing the modified date. It is ideal for author changes or retention label updates. When to use UpdateOverwriteVersion UpdateOverwriteVersion updates metadata and creates a new version. It is required for editor changes because SystemUpdate does not update the editor field reliably.