You may notice some ghost cards on your story map after having imported from Jira, or when updating epic links. Ghost cards look like this:
Ghost cards are a placeholder for when the hierarchy isn't available to place a story or a step. When you initially import from Jira, we recommend trying to get your journey and step backbone in order fairly early, enabling you to move stories into their relevant hierarchy and remove ghost cards.
Try to use Avion if you need to manipulate your backbone structure, as opposed to Jira.