Possibly and issue that the recovery uses one of the ndmp client definitions that doesn't have the correct credentials set yet, as NDMP recoveries might reference any of the defined NMDP client instances, even one that isn't actively used anymore and might have still incorrect entries.So try to correct the credentials in all definitions fro that NDMP client, not just the one(s) used for backup that are working fine.See also KB [URL] and [URL] stating the same.I also tend to use "ndmpsup -c [ndmp_client_name]" to validate credentials from the CLI, talking to the NDMP client in question, being able to see it NMDP related configuration, so one doesn't even need to run a backup to validate altered credentials.      
I am getting an error when trying to recover with the Networker user GUI 42597:nsrndmp_recover: connect auth: connection has not been authorized 42610:nsrndmp_recover: The NDMP connection is not successfully authorized on host  42847:nsrndmp_recover: Not able to connect or authorize the recover host    I recently set the remote user field with the correct ndmp user account and password as backups were failing after a domain migration. now recovery seems to not be working.
nsrndmp_recover Error the connection has not been authorized