I've just noticed that the said router actually is obsolete:
The firmware upgrades are approximately three years old see below:
Would you be able to upgrade my router to a new router which will be supported with firmware upgrades for several years?
Rosie & James
Welcome to the Community!
We were able to locate your account using your community details and understand that you've reached our Tech team.
They've requested for a new NBN router and updates will be given as soon as it becomes available.
Let us know if you need further assistance.