Not able to see user under Link an Existing User Account

Summary:

One employee was converted on 4/24/2023 from Pending worker to Employee.

There is already User Account created for an employee in security console and account is not automatically mapped to Employee record.

When trying to map this account with User Account->Link an Existing User Account particular account which is already exists in Security console not visible in dropdown.

Please let me know how I can link account and employee record so that employee can get autoprovisioned roles.

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