When a Manager or Approver has been archived you may find that they still display on an Employee's card as they are still technically entered as the Employee's Manager/Approver in the background.
The information on the Employee Card is static and based on the information that has been manually entered and held against the Employee.
On the Job Change page, when a Manager/Approver is Archived the user is removed as an option in the dropdown list, causing it to default to the first person. This however is not recognised as a change, it is only the default action of the dropdown field, and therefore does not replace the information displaying on the Card with the default name now showing on the dropdown list.
Similarly Reports use live data, so we expect that the Approver displays as 'not found' because their chosen one is not available and the 'default' does not count as 'entered data' to then be reported on.
To resolve this display you can simply goes into the Change page of the Employee and manually update the Manager/Approver. This entered data will then reflect correctly on the Employee Card, Change page and in Reports.