Are you sure that kind of drive/media even supports low-level format? It might not, or possibly it requires a different procedure.
The obvious things are termination on the drive and the DIP switch settings - make sure these are set for IBM PC and I would set the terminator power to drive only. It might just be using diodes since the quick setup manual says the factory default is to provide terminator power from both the drive and cable/host - but on most SCSI devices that is a bad idea. I'd pick either but not both and for a drive that lives inside the PC on the same PSU as the mobo it would be best to use drive power.
Lastly the manual says the "floppy" must be partitioned for DOS. I'm going to assume it's visible to the system as removable HDD, therefore the same would apply to any Win9x. There's a software tool for that, but it's not required if the media comes pre-formatted (for IBM PC). Does is say anything about that on the box?