In the appliance console of Symantec Endpoint Detection and Response (SEDR), the system health monitor displays the alert "Connection to Symantec EDR Cloud has failed". On Settings> Global, the status of edrc.symantec.com is "Unknown Host"
You will also see a failed attempt to connect in the results of status_check:
The EDRC web service was discontinued by BROADCOM on 10/19/2020.
Within EDR Appliance console, please disable all EDR appliance features related to EDRC.