I tried figuring out with my xen server.
I couldn't even run any xe vm-list to check the VMs, and as well,
connect via XCP-NG center.
From the console it shows no VMS.
All of our servers are running on XCP-NG, And some have been added to the pool,
But there's a problem when we had a power issue, All the VMs goes down and doesn't boot up automatically,
1 - I have enabled power on through xcp-ng by login in via ssh,
2 - I have checked it and it's also enabled via XCP-NG Center, With autostart on,
3 - I have also checked it through Xen Orchestra, And it's enabled.
But when we had issues, I have to start the VMs manually.