PiHole not responding to Router Solicitation requests

[marsfan]

@Bucking_Horn

However, if you had disabled router advertisements altogether , then your network would now lack IPv6 connectivity, in lieu of a prefix and a router, at least for those clients that use SLAAC exclusively (e.g. Androids).
In addition, that lack of an IPv6 prefix may also prevent your Pi-hole from producing RAs.

So this might be part of the issue. I disabled RA via SLAAC on my router, as I literally cannot find a way to remove it's ipv6 address from the RDNSS broadcast (it seems to be hardcoded into the program somewhere, I am in the process of digging through the source code). I thought that enabling SLAAC+RA on the pihole would completely take over from what the router was doing, but you are implying that it does not.

Here is the output from running the command your recommended:

/var/log/pihole.log:16624:Aug  3 17:33:06 dnsmasq[8221]: started, version pi-hole-2.85 cachesize 10000
/var/log/pihole.log-16625-Aug  3 17:33:06 dnsmasq[8221]: compile time options: IPv6 GNU-getopt no-DBus no-UBus no-i18n IDN DHCP DHCPv6 Lua TFTP no-conntrack ipset auth cryptohash DNSSEC loop-detect inotify dumpfile
/var/log/pihole.log-16626-Aug  3 17:33:06 dnsmasq-dhcp[8221]: DHCP, IP range 10.0.0.10 -- 10.0.0.255, lease time 1d
/var/log/pihole.log-16627-Aug  3 17:33:06 dnsmasq-dhcp[8221]: DHCPv6, IP range ::100 -- ::1ff, lease time 1d, template for eth0
/var/log/pihole.log-16628-Aug  3 17:33:06 dnsmasq-dhcp[8221]: DHCPv4-derived IPv6 names on eth0
/var/log/pihole.log-16629-Aug  3 17:33:06 dnsmasq-dhcp[8221]: router advertisement on eth0
/var/log/pihole.log-16630-Aug  3 17:33:06 dnsmasq[8221]: using only locally-known addresses for domain lan
/var/log/pihole.log-16631-Aug  3 17:33:06 dnsmasq[8221]: using only locally-known addresses for domain use-application-dns.net
/var/log/pihole.log-16632-Aug  3 17:33:06 dnsmasq[8221]: using nameserver 2606:4700:4700::1001#53
/var/log/pihole.log-16633-Aug  3 17:33:06 dnsmasq[8221]: using nameserver 2606:4700:4700::1111#53
/var/log/pihole.log-16634-Aug  3 17:33:06 dnsmasq[8221]: using nameserver 1.0.0.1#53
/var/log/pihole.log-16635-Aug  3 17:33:06 dnsmasq[8221]: using nameserver 1.1.1.1#53
/var/log/pihole.log-16636-Aug  3 17:33:06 dnsmasq[8221]: using nameserver 2001:4860:4860::8844#53

Here is the settings I have configured on my pi-hole

Here is my router's DNS/DHCP settings.

I found that if I do not uncheck the Announce IPv6 on LAN (SLAAC) option, no matter what I do, my router will provide itself as an IPv6 DNS server, in addition to the custom dnsmasq configuration settings that I have set into it.