I can see on our systems your NBN-FTTP 100/40 service is UP, but not authenticated.
Your modem should be connected to the UNI-D 2 port.
Your modem is not a TPG supplied modem, so support configuring it is ultimately up to you.
But, i will try and help.
You need to configure it with your TPG USERNAME and PASSWORD.
Here is the guide to configure our TPG supplied FTTP modem.
Yes its the same un/pw u use to log into TPG.
I doubt its something on our end, but hard to say at this stage.
Your modem could def by faulty. Im not saying to buy another one, but if u had a different FTTP type modem to try that would help TS.