We still need to check if a firmware update is available for the make & model of your current modem.
I've ran a quick test and have detected that your modem is currently detecting a sync speed of 106Mbps from the line which you can confirm when you log in to your modem's user interface. It appears that the problem is getting the result to show up on your devices.
We've created some articles that will help you improve your home Wi-Fi network.
I have also arranged a call back to be made on 02 FEB 2021 (PM) from our Technical Team to assist you in checking for any underlying issues that may be present.
Should you require further assistance, you may reach out to us again or you may check out our self-help options located here: http://tpg.com.au/support
Hi @garytootell, your issue has been raised to our Technical Team and one of our Senior Technical Specialists will be in touch for further assistance. If there's a need for us to replace a router, you will be advised.
Kindly await a call within the day.