NDMP restore failing but reports successful

I have not had any issues with Networker restoring files from an NDMP backup to a data domain in the past, but suddenly I'm seeing this:

Recovering files of client 'client0' from server 'networker_server'.
Recovering 1 file into its original location
Total estimated disk space needed for recover is 592 KB.
Requesting 1 file(s), this may take a while...
03/09/21 12:25:27.808469 NDMP Service Debug: The process id for NDMP service is 0x29366a28
42795:nsrndmp_recover: Performing recover from Non-NDMP type of device
03/09/21 12:25:28.074001 NDMP Service Debug: The process id for NDMP service is 0x29366a28
85183:nsrndmp_recover: DSA is listening for an NDMP data connection on: server_ip, port = 9483
42689:nsrndmp_recover: Performing DAR Recovery..
86724:nsrdsa_recover: DSA listening at: host 'networker_server', IP address 'server_ip', port '9483'.
42938:nsrdsa_recover: Performing Direct File Access Restore
42940:nsrdsa_recover: Reading Data...
42617:nsrndmp_recover: NDMP Service Log: server_archive: emctar vol 1, 1 files, 262144 bytes read, 0 bytes written
42927:nsrndmp_recover: Successfully done

It says the restore is successful, but the bytes written are zero and the file has obviously not restored. I can find no reason for the failure to actually write the file back to the client. This is Networker version 8.2.4, which is old but has worked without issue in the past.