Welcome to TPG Community!
We were able to locate your account using your community details and have run some remote test.
We weren't able to detect any fault within the NBN network and it also shows that the service has been stable for more than a week now.
We've seen that you are under our basic NBN 12/1 speed tier in which multiple devices working on the internet may cause the slow connection due to bandwidth sharing.
We've created an article which will guide you in choosing the best NBN plan for you. Check this link.
We also have an article for troubleshooting a slow internet connection. Check it here.
Should you require further assistance, please let us know.