Welcome to 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, it is handle by our Technical Escalation Team and we've seen that the NBN box has been replaced, at the moment it still under investigation, further updates will be provided when it becomes available.
Should you need further assistance, feel free to search community for help or chat with us at https://www.tpg.com.au/support/contact/ and we'd be glad to assist you.