I've noticed that the virtual links can be hard to find because the page where they are shown it is set to only show the last 7 days of links created. If you change or extend this time period then you should be able to edit the past links created. And there are certain aspects of the Virtual Links that cannot be edited once created so you would want to inactivate or delete the old link and recreate it if you cannot update the part of the link you setup.