Hello Nik,
Sorry for the confusion, I did not try the solution myself, as I use Synology NAS boxes. I was interessed in the issue and searched for it, so I could maybe supply an answer or atleast a direction for the solution.
Regarding the prefix “WORKGROUP\” this is AFAIK the default setting for a Samba configuration and the Samba package is used by by NAS boxes for the SMB functionality.