For customers experiencing any issues with their NBN service, we recommend the best thing to do first is check if there's an outage on the NBN network.
We have created this article that can guide you on How to Check for NBN Network Outage
If there are no known outages in your area, customers can proceed with the troubleshooting steps indicated on this link : https://www.tpg.com.au/support/nbn-fttn/problems_connect_internet_nbn_fttn
We understand that you were able to reach our Tech team and learned that the WLAN of your modem/router was Off, which is why the internet through WiFi is not working.
The service was working with your WiFi service after turning On the WLAN.
Feel free to search Community for help with your issue, or contact us and we'd be glad to assist you.