External IP not getting assigned using New-CIvApp and Start-CIvApp

I have created a new vApp with...

Get-CIVAppTemplate -Name $myTemplate -Catalog $catalog  | New-CIVApp -Name $newvapp -Description "This vApp is created from the vApp template named MySourceTemplate." -OrgVdc $myOrgVdc

Then I set the vApp network with...

$myVApp = Get-CIVapp -Name $newvapp 

$myOrgNetwork = Get-OrgNetwork -Name 'DEV_TC_TEA_Routed_Network'

Get-CIVAppNetwork -VApp $myVApp -Name 'vAppNet-vAppNet' | Set-CIVAppNetwork -FirewallEnabled:$false -NatEnabled:$true -ParentOrgNetwork $myOrgNetwork

Then I start the vApp with...

$myVApp | Start-CIVApp

But the External IP (which is configured based on the routed network) is not assigned. Any ideas?

I tried using the CustomizeOnInstantiate option as follows...

New-CIVApp -Name $newvapp -Description "This vApp is created from the vApp template named MySourceTemplate." -OrgVdc $myOrgVdc -CustomizeOnInstantiate

...but I get an error stating CustomizeOnInstantiate is an unknown option

New-CIVApp : A parameter cannot be found that matches parameter name

'CustomizeOnInstantiate'.

At D:\apps\vCloud\Scripts\Catalog-Clone-Start_DEV_TC_AUTO.ps1:22 char:186

+ ... gVdc $myOrgVdc -CustomizeOnInstantiate:$true

+                    ~~~~~~~~~~~~~~~~~~~~~~~~

    + CategoryInfo          : InvalidArgument: (:) [New-CIVApp], ParameterBind

   ingException

    + FullyQualifiedErrorId : NamedParameterNotFound,VMware.VimAutomation.Clou

   d.Commands.Cmdlets.NewCIVApp