KB1198: NFC connectivity troubleshooting steps
https://www.veeam.com/kb119826.08.2011 · Try adding the ESXi host the VM is on as a standalone host to Veeam, then create a backup job to pull the VM from the standalone host. (This will help isolate if the Management Agents need to be restarted on the ESXi host) Remember to remove the job and standalone host from Veeam's configuration after the issue is resolved.