Hi Jeramie,
This problem occurs if the User profile was trashed. This won't reflect in search result as the search excludes deleted Tickets/Users.
You can find the User profile from Admin>Contacts and filter for Deleted Contacts, once you restore it, you should find the option to update the profile.
Hope this helps!!
Jeramie Vargas
I need to update my email address but prompts an error:
I searched if the email is already been taken but no results found, neither in requesters nor agents list