QNAP admin issues

I’ve set my QNAP NAS up with a different administrator user and disabled the standard “admin” user. I’ve done this for security purposes, as it will be a lot harder to access the machine remotely now.

However I find that even though I can still browse to the NAS from my Mac Mini as a guest my ROCK cannot see the drive at all, either via the host name or the IP address. As soon as I enable the admin user it works fine.

I have a similar problem with my second QNAP NAS in a different location.

Any thoughts?