Hi @Johnny_Liu
Welcome to the Community!
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
We understand that you've been in touch with our Tech team and the case was raised to our Engineers for further investigation as there's a possible fault within the NBN line. An assigned Engineer will be in touch with you via SMS or phone call within 24 to 48 hours.
BasilDV
