When trying to filter for a single user ("inherited" in this example) in the Administrative Activities report, that user cannot be selected.
When the report is generated without any filter, the user is in the report.
Privileged Access Manager, version 4.1.7 and below
The user "inherited" had their Credential Manager group inherited. The underlying SQL query generates the list of Credential Manager users based on the groups directly assigned to the users. Any user which has their CM group inherited will not be listed.