Hyper-V export with Export-VM to network (NAS) fails

Question

I am trying to export Hyper-V virtual machine from Windows Server to network disk (NAS). And if change only the path to another network disk (NAS) it works as expected.

I am running powershell with interactive user account (Administrator) on server and I have checked all user rights on both NAS devices disks. They are accessible and with all rights. Error description is not very helpfull.

Export-VM -Name "Hakopirtti-HA" -Path "\\192.168.1.20\levy\HA-Backups\-HA-VM"
Export-VM : Export failed for virtual machine 'Hakopirtti-HA'.
At C:\Hyper-V_Backup\VMCopy.ps1:41 char:1
+ Export-VM -Name "Hakopirtti-HA" -Path "\\192.168.1.20\levy\HA-Backups ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Export-VM], VirtualizationException
    + FullyQualifiedErrorId : OperationFailed,Microsoft.HyperV.PowerShell.Commands.ExportVM

# This works as expected
# Export-VM -Name "Hakopirtti-HA" -Path "\\192.168.1.15\Volume_1\ExportedVM2"