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
If there are no known outages in your area, customers can proceed with the troubleshooting steps indicated on this link : https://www.tpg.com.au/support/nbn-fttn/problems_connect_internet_nbn_fttn
In your case, the synchronization between the node and the modem is stable, which is an indication that there's no line fault affecting the service.
Further investigation may be required to identify what is really dropping out as it could be the Wireless connection, if you're connecting all your devices via Wi-Fi.
Wireless dropout can be eliminated by using a wired connection. If the connection will not drop on a wired device, it is likely a wireless drop outs issue and we recommend having a read of this community article which may help improve the wireless connectivity performance : Easy Steps to Improve Wi-Fi Connection In Your Home
Otherwise, feel free to search Community for help or contact us and we'd be glad to assist you.