David,
I remember having quite some ‘fun’ getting my path to work. There are a couple of threads dealing with it here. Try this one…
May I suggest (in your case):
\\192.168.4.103
that is, no smb; and/or
\\192.168.4.103\Roonbackup
etc?
The fact that you can get to it via Samba is a good sign: IOW, you’re close 