Welcome to the community!
We recommend to check if there's an outage on the NBN network affecting your service. 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 you may perform basic troubleshooting, we did an article that you may find helpful see this link below.
In this case , we've seen that this issue has been raised to our Engineering Team and was escalated to NBN Co. Initial test result shows a possible line fault causing the service not to work. One of our Engineers sent you an SMS about the NBN Technician appointment schedule.
Let us know should you require further assistance.