After further checking, found out the error is referring to the Veeam host not able to get UUID instead of the CentOS VM.
Once make sure the Veeam host (which also as VM in the same Proxmox host) is able to get the UUID, the issue is solved...
Trying to setup CentOS 9 VM as Veeam Hardened Repository but encounter below error. From forum there is suggestion to change the machine type but i have try version 8.0 on i440fx and q35, still not working. Any idea...