Information
Data from journald should be kept in the confines of the service and not forwarded on to other services.
Rationale:
IF journald is the method for capturing logs, all logs of the system should be handled by journald and not forwarded to other logging mechanisms.
Note: This recommendation only applies if journald is the chosen method for client side logging. Do not apply this recommendation if rsyslog is used.
Solution
Edit the /etc/systemd/journald.conf file and ensure that ForwardToSyslog=yes is removed.
Restart the service:
# systemctl restart systemd-journald.service