Android device bipasses pi-hole

[Watchreader]

I just got a raspberry pi 4, I installed pihole, and it works pretty great for all the devices that use it as a DNS server. Except my Galaxy S5e, running android 11. I've tried both Chrome and Samsung Internet, and nether of them go through pi-hole.

What's unusual about my setup is: my ISP is Google Fiber, and it has a fairly simple interface (which means I can't do fancy things like dnsmasq as far as I know). I've set the router to use pi-hole as its DNS, but it doesn't push these settings out to other devices.

I've read this thread: Pi-Hole works everywhere except Android Phones

And many other threads which tell me to:
a) Turn off Private DNS (this was never enabled for me, so done)
b) Only specify my pi-hole IP as a DNS provider for DNS1, then specify some nonsense (127.0.0.1) for DNS 2
c) Uninstall com.android.partnerbrowsercustomizations.chromeHomepage from my tablet (it was never installed in the first place)
d) Do weird things with chrome dns settings (these settings don't appear for me).

What's also notable is that my tablet can get to the pihole interface if I use the IP, but not the hostname. So it really doesn't seem to use pi hole at all, even though it's specified as a DNS server. At the same time, I'm seeing some entries in the pi hole logs as coming from my tablet, but only sporadic ones for google.com.

[Bucking_Horn]

@Watchreader

What's also notable is that my tablet can get to the pihole interface if I use the IP, but not the hostname.

This is a strong indication that your Android tablet would not use Pi-hole for DNS, but some alternative. I suspect that to be your router's IPv6 address.

You should check your router's IPv6 DNS section:
Likely, your router is advertising its own IPv6 address as DNS server, allowing your clients to by-pass Pi-hole.

You'd have to find a way to configure your router to advertise your Pi-hole host machine's IPv6 as DNS server or to stop advertising its own.

You'd have to consult your router's documentation sources on further details for its IPv6 configuration options.

If your router doesn't support configuring IPv6 DNS, you could consider disabling IPv6 altogether.

If your router doesn't support that either, your clients will always be able to bypass Pi-hole via IPv6.

[Watchreader]

I was afraid of something like that. Thanks!