For a client to backup to a storage node, you need to ensure that the Storage Node resource of the client has the name of the storage node. By default, it is nsrserverhost which means it would backup to the device attached to the nsr server.

Check this and update the result to help understand further.

Maybe I didn't explain it well enough. Not trying to backup a client to the Storage node...the storage node is the one I am trying to backup, but it wants to write to the jukebox on the NW server instead of its own jukebox. This just started a week ago. Been running fine for a couple of years until now. No changes have been made.

Storage node is the client as well - have you checked storage node field for that client? Actually, can you post nsradmin dump for that client to see configuration and log which shows such behavior?

You still need to have the SN field with its own host name and the media for this pool labelled on the storage node.