If you want to easily check your own router, you can use any DNS Gateway (NextDNS, Cloudflare Gateway Pi-Hole etc.) Just be sure to set the DNS servers under "Advanced->Network->Internet->Advanced Settings" because the DHCP DNS server setting will only apply to the devices inside the network, not the router itself.
src - https://www.reddit.com/r/hardware/comments/tbthjj
src - https://www.reddit.com/r/hardware/comments/tbthjj