Which devices are dropping internet? Archer or Gen2? Ethernet or wifi?
How long is the dropout? How often does it occur?
How do you recover from it?
Can you do without the Gen2 for a while to prove it is the cause?
Have you looked at the system logs for both routers? Archer log might have info if you exclude voip messages.
What happens with the lights on Archer and nbn box with dropout?