When Netvault server language is set to Chinese Simplified, backups will be stuck in "Waiting for media" when physical tape drive is selected in target set.
This also happens when physical tape drive is added when Netvault server language is set to Chinese Simplified, after which Netvault server language is set to English.
Using "Any Device" in target set will still see the backups correctly going to the physical tape drive if the physical tape drive is the only device.
Reinstall Netvault server in English and add the physical tape drive in English. Do not change the Netvault server language back to Chinese.
Recreate the target set and backups should function correctly with the physical tape drive.
Note: It is possible to backup the Netvault database and restore back the configuration after the reinstall is performed. During the restore of Netvault database, please do not restore media management, as it will bring back the device with the language issue.
Waiting for fix in a future release of NetVault Backup.