Thanks for raising this to us. We have an existing thread on how to set up 3rd party mesh/routers please see the links below.
Note: TPG do not support 3rd party mesh or routers, to avoid incorrect troubleshooting we recommend to contact manufacturer support.
Let me know should you require further assistance.
I tried to connect my d-link home mesh wifi system to the tpg modem but it said connected but no internet. Can you please assist in the set up?
I plug in the cable to Internet slot in my Dlink device and the other end to LAN1 slot in modern. But didn't work.