How to fix a mysterious old User ID that only appears when sharing a dashboard?

[Nancy Bonanno]

We have a user whose User ID is messed up somewhere.  Let's call her Anita Hammer, Manager of Delicate Computer Repairs.  She was a contractor and her ID was ah123456.  Then she was hired as a fulltime employee and her ID became ah567890.  In Crowd, it is ah567890.  In Jira, if you add her to a filter, she is ah567890.

But if you try to add her as the editor on a dashboard, suddenly the only ID that appears is ah123456, and because the rest of Jira doesn't recognize that ID, it doesn't work and she can't edit the dashboard.

We've combed through Crowd.  We've combed through Jira User Management.  It seems to be correct everywhere...except when you try to share a dashboard with her.

Has anyone got any ideas or suggestions?