The ACD field settings on the Agent Login ID screen take precedence over the system-wide settings on the Feature-Related System Parameters screen.
If any field value is set to system on the Agent Login ID screen, the system-wide setting is applied.
The system field value is the default setting for both new and upgraded systems.
The settings on the Feature-Related System Parameters or the Agent Login ID screen override the default setting and apply to both ACD and DA calls.
The agent must log out and log in again for the changes to take effect.