Welcome to the Community!
We were able to locate your account using your community details and learned that you are under the NBN HFC service.
We've tested the line and was not able to detect any fault within the NBN network.
Based on the subject of your post, we can assume that you are referring to the WiFi signal of your modem/router.
WiFi is prone to signal interference that may have caused the issues within your network.
We've created some articles that will help you improve your home WiFi network. Refer to these links:
Let us know how it goes.