The CHKUSR utility was run from the command line outside of the Agent, without the pam_service argument defined; then instead of using the service name from the oscomponent.auth.pam.svc property in the agentparm.txt file, it used the default login name.
Component: Workload Automation Agent
The CHKUSR utility, if running standalone (i.e. with no connection to the Agent), will not read the content of the agentparm.txt file. As such, it is expected for one to use either explicitly defined service name or the default login if the pam_service argument was omitted.
The value of the oscomponent.auth.pam.svc property would be read only if the instruction to launch the CHKUSR utility had come from the scheduler's submitted job, i.e. the utility was executed by the Agent.