Netapp VMDK eager zero Best Practices

I am looking for clarification on the best practices in using the Netapp ontapp 8.2.2 with VM~thin provision.  My understanding is the best practice is to make sure the flex volume is thin provisioned and that the Lun is also thin Provision.  However what I don’t understand is what the best practice is at the VMDK level.  My understanding was that you would set the hard disc as Thick  eager Zeroed  This will write Zeroed data to the hard disc but the Netapp through VAAI connection would understand what was happening at the ESXI level and in turn not allocate the space at the Agg level.  However my testing here is showing that when we thick provision eager Zero the space also gets allocated at the Netapp aggregate level.  I have confirmed as expected that thin provisioned and Thick Lazy  at the VMDK does not allocate the space at the netapp.  .  What I’m trying to understand is whether I have configured the VAAI connection incorrectly or whether this is the expected behavior.  This is being used as a iscsi not NFS
Your thoughts are greatly appreciated.