Management Center is showing an error message "Unable to reach device" under the Web Security Service (WSS) device when navigating to Network > Manage Devices.
When testing connectivity under the Connection Parameter tab. Connection Status shows successful.
Management Center is able to push policy to the WSS.
Web Security Service
Universal Policy Enforcement
The issue was caused by Management Center losing connection to the WSS and the status getting stuck in this state.
To resolve this cosmetic issue. You will need to change the Health Monitoring State from Activate to Deactivate, then back to Activate Devices.
The process will force Management Center to reset the Health Monitoring State back to Normal.
Note: The device status can take up to 30 seconds to change.