Drop-in Gateway DNS & ipv6 issues

Hello community !

I’ve been having great fun tuning my shadow router, however, I have an issue with the Drop-in Gateway.

I have managed to correctly setup my shadow as a drop-in gateway following official documentation (DHCP on my main ISP router is therefore deactivated). I have the exact following setup

The reason why I need the drop-in gateway is for the following

  • SQM management for mitigating bufferbloat
  • Override DNS settings for all clients
  • Wireguard server for out of home office work

I ran into the following issues

  • DNS adresses reported by ip-leak.net from my client devices show my main router ISP DNS, not the Cloudflare DNS setup on my shadow router.
  • test-ipv6.com shows ipv6 connectivity though my shadow has ipv6 turned off. Main ISP router has ipv6 turned ON but funny enough when I deactivate that feature, my bandwidth goes from 300 Mbps to 80 Mbps (I managed to notice that as I use cloudflare speedtest to verify my SQM settings)

Thanks for your help !