Having an issue doing an NDMP Netbackup restore to Cmode NetApp

Hello,
I have a NetBackup Windows master server, running NB 7.7.3. It's only used for restored, and we can't upgrade to a supported NB version (so no Veritas support). I'm trying to do an NDMP restore from a NetApp 7mode backup to a cmode cluster. Its the first time we've gotten a request of this type. The old NetApp has since been decommissioned. I added the credentials off the new netapp to the legacy NB master...no issues with that. But when I do the restore, I get an error:

Error ndmpagent (pid=30764) CmodeClusterName: Unable to lookup actual name for vserver 'cmodevservername'. Ensure specified vserver exists.

Not sure how to remediate. The destination folder on the cmode netapp is:  /CmodeVserverName/restorevol/ where "restorevol" is a volume used for restores in the CmodeVserverName vserver.

Thanks