After checking your FTTN (fibre to the node service) is live, depending on modem connected ( needs VDSL compatible one) it may need your username & password programming.
Read our TPG Community article on how to set up your NBN FTTN service. The video is followed by a step by step guide. Visit https://link.tpg.com.au/FTTN/B.
I have done some remote test and noted that there is sync but no authentication, nbn portal test are also showing line state up and stable so i believe could be modem require configuration. see below link for FTTN set up and how to configure your modem. Hopefully this will resolve your issue.