I followed your instructions and created the new user “ max2play“ on the diskstation and it worked !!
This mounted and worked when I accessed through the squeezebox server interface.
Then I tried another mount, to access my video folder on the NAS
This also loaded but in squeezebox server I can see only one folder “ music“ .The video folder is not visible. I think I need to create separate folders on the pi to give separate targets ie /mnt/share/music and /mnt/share/videos to give each share a proper path. Is this what is required or should it have worked the way I did it ?