When the back up destination is a network share, Windows Server Backup only saves the most current system image, overwriting the previous backup each time it runs.
This is hardly a backup as a failed backup will obviously fail to save anything, but it will likely destroy the previous backup in the process as that’s what it’s been programmed to do (save most current image only).
The only way and the recommended way to have multiple images saved is to set the backup destination to disk. This is also hardly a backup as it requires a physical disk to be installed locally and dedicated for backups, when the whole goal of backups is to get the data off of the local computer.
Luckily my NAS server is capable of sharing iSCSI targets and so I provisioned a 1TB disk to the server via iSCSI software initiator. I followed the instructions here even though I don’t have a netgear, the screenshots were pretty useful: https://kb.netgear.com/28432/How-do-I-back-up-data-from-a-Windows-Server-to-an-iSCSI-LUN-on-a-ReadyNAS-OS-6-system.
There was also a youtube video I watched on setting up iSCSI on FreeNAS to get the juices going: https://www.youtube.com/watch?v=8FO9VYgKWdQ.
Will have to wait for tonight’s backup run at 9pm to see if it worked or not!