Welcome to the Community @Leolsc
Before attempting the troubleshooting steps, TPG recommends that you:
2. "Power cycle" your ADSL/NBN modem. This means turning your modem off and waiting for one minute before turning it back on again. This allows your modem to reestablish connection to our server.
If your service is not affected by an outage, then you may proceed with the troubleshooting with the help of our online guide: https://www.tpg.com.au/support/problems_connect_internet.php , https://www.tpg.com.au/support/nbn/troubleshooting.
Otherwise, feel free to search Community for help or contact us and we'd be glad to assist you.