At work we have a Draytek Vigor 2830 router which although the backend is way more complicated than I'm used to I've been fine with port forwarding and the usual basic router tasks. However my boss recently got a Lacie NAS drive with the built in dyndns function which we wanted to take advantage of so clients could login and download video files directly from us having to manually upload to our FTP.

Now I can access the NAS on the internal network no problem, forwarded the correct ports and the Lacie network assistant tells me everything is green & fine, however the dyndns just doesn't update and upon closer inspection I realised the ethernet port on the router is Orange and this may be the culprit.

I took the NAS drive home and plugged it in to my basic router, everything's fine and the ethernet port flashes green and the NAS drive can update the IP through dyndns.
Is there something I'm missing in the router settings apart from the port forwarding or am I possibly not doing that correctly either?

Any help to point me in the right direction would be greatly appreciated, cheers.