Veeam Management Agents are offline after Veeam Service ...
https://www.veeam.com/kb413016.03.2021 · All Veeam Management Agents are offline after VSPC upgrade Cause This may be caused by an incorrect security certificate configuration which leads to disconnection of management agent on the Cloud Connect server after upgrade. See the More Information section for details on how to properly install security certificates for VSPC. Solution