hi,
got exactly same issue, to fix it you just need add " before and after password
if your password is password on your NAS enter “password” in volumio password field.
looks like syntax
mount -t cifs -o user=me,password=password //192.168.1.1/music /music is replaced by
mount -t cifs -o user=me,password=“password” //192.168.1.1/music /music