Welcome the community!
If you're having issues with 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 you may perform basic troubleshooting, we did an article that you may find helpful see this link below.
In this particular case, we've seen that there has been an issue with NBN Co.'s network affecting multiple service and declared fix. At the moment the service has been connected for 1d 20h 30m.
Let us know should you require further assistance.