The same effect as re-registering a VM can be achieved with a Reload-VM operation like this:
On the ESXi shell via SSH or DCUI:
Get the VM id with:
# vim-cmd vmsvc/getallvms | grep -i [VM-Name]
Execute a reload:
# vim-cmd vmsvc/reload [VM-ID]
Via PowerCLI:
(Get-VM [VM-Name] | Get-View).Reload()
Check if that updates the information properly.
If it still doesn't check if a restart of the host management agents works.
