"Get-PartnerCustomerUser" with "-ReturnDeletedUsers:$false" returns 0 for some customers

Copied from docs issue #112

"Get-PartnerCustomerUser" with "-ReturnDeletedUsers:$false" returns 0 for some customers.
I'm sure the customer in question has users that is not deleted, and it works for 7 out of 11 customers.

I'm specifying "-ReturnDeletedUsers:$false" because I like having available parameters visible in scripts no matter if I use them or not. Easier for troubleshooting later on.

PartnerCenter module version: 3.0.7

Reproduce

PS C:\Users\OlavRønnestadBirkela> 
# Without -ReturnDeletedUsers:$false
$Users = Get-PartnerCustomerUser -CustomerId $CustomerId;$Users.'Count'
$Users | Group-Object -Property 'State' -NoElement
518

Count Name                     
----- ----                     
  518 Active                   



PS C:\Users\OlavRønnestadBirkela> 
# With -ReturnDeletedUsers:$false
$Users = Get-PartnerCustomerUser -CustomerId $CustomerId -ReturnDeletedUsers:$false;$Users.'Count'
$Users | Group-Object -Property 'State' -NoElement
0

PS C:\Users\OlavRønnestadBirkela> 

The required code changes to address this issue have been made