I don't know the HomeHub, but can I assume it has Network Address Translation (NAT)? Most home gateways do, and if so, then devices behind it are not actually
on the Internet, they are on a private network with a different IP address range. The typical
private range of 192.168.xxx.xxx is one of several that are not actually valid on the Internet, and routers will not forward them.
So, behind NAT, nothing gets through unless an
outgoing port is opened on it, and that happens in two ways: explicitly by a Port Forwarding setting on the gateway, or by some application that has a persistent attachment to the Internet.
In your case, in my opinion, that points the finger directly at the MioNet function on the NAS box. I would disable it, and also check the HomeHub for any Port Forwarding settings. (The only ones there should be ones that you
know you need - if in doubt, make a note of them, then
remove them and see if anything breaks.)
A friend of mine has a WD NAS box that he uses behind his home hub. When I visited him back in August he was annoyed that MioNet was asking him to pay for an account, but when I read about it, I learned that MioNet is
specifically for getting to your files from outside, from the Internet, If you don't need to do that, you don't need MioNet - full stop. We stripped it off all the PCs in my friend's house (he has a lot), and set the WD box as a plain SMB share on Windows (\\wdstorage). Sorted.
