Welcome to the Community @Petejo
Before performing any troubleshooting steps, we advise our customers to check if their location or area is affected by a planned or unplanned network outage. We've created an article on How to Check for NBN Network Outage.
Once confirmed that the service is not affected by an outage, then you may proceed to troubleshoot the internet issues. We've created an online guide to perform. It is available here.
In your case, the internet issue was caused by a faulty NBN NTD box. The NBN technician that attended the site replaced the faulty device and resolved the issue. The modem shows a stable connection and performing within specification.
If you need further assistance, please let us know.