There is no System Monitor available in the Administration and Monitoring Station, only the Processing Monitor.
It is expected behavior if there are no Tenants created in the FlexiCapture installation.
As it is described in the Online Help, the System Monitor is designed to monitor the performance and workload for both the entire multitenant system and each Tenant individually.
If there are no Tenants in your FlexiCapture installation, the System Monitor is not available.
System Monitor is not needed for the installations without the Tenants, as all the information for the main Tenant is available in the Processing Monitor.
The Tenants can be created in the Administration and Monitoring Station > Settings > Tenants > New Tenant: