Hi @sampollard . Have a look at the Accepted Solution in this thread. It is for Archer C9 but could be similar to your C50. It relates to setting VLAN ID=2.
The Amber UNI-D1 light indicates a 10/100Mbps device. C50 only has 10/100Mbps ports, which might limit your top speed.
Thanks for the suggestion, I have now tried this and many other suggested settings, this is shaping up to be very complicated and confusing. I really thought I'd just be able to plug in a router and use the internet. I've tried dozens of suggested settings and it seems that the further I look the worse it gets. I really need access to the internet ASAP, this sucks.
@sampollard . Do a factory reset first.
Operation Mode is Wireless Router.
Settings are PPPoE, username + @tpg.com.au, password.
If you are on bundled NBN/VOIP plan, you need VLAN ID=2 as described above.
If you are on BYO router data-only plan, VLAN ID is not used.
Look at the router's System Log; there might be a clue there.