User profile showing up twice in SharePoint

Ok. So, I’m not sure where to begin here but here it goes!

Can someone tell me where the “Org Chart” (SP on-Prem 2016) on sharepoint pulls user info from? I show a user who’s name displays twice. One instance from our old domain (no longer exists) and another instance from our current and existing domain. This is causing an issue and I can’t find anything that can lead me to edit it other than the UIL which is not editable.