On the NetBackup media server, the ECA health check shows the warning, 'hostname missing'
This issue occurs because media server FQDNs are not added during CSR generation. Hence, during ECA health check, the CERTIFICATE_SAN_HOSTNAME_VALIDATION check returns a WARN status on media servers. (IA-35366)
Workaround:
This issue can be ignored as there is no loss in functionality.