Firefox has an official way to disable that. https://support.mozilla.org/en-US/kb/configuring-networks-di...
All Pi-hole instances use it by default. https://github.com/pi-hole/pi-hole/releases/tag/v4.4
All Pi-hole instances use it by default. https://github.com/pi-hole/pi-hole/releases/tag/v4.4
> Note: The canary domain only applies to users who have DoH enabled as the default option. It does not apply for users who have made the choice to turn on DoH by themselves.
https://support.mozilla.org/en-US/kb/canary-domain-use-appli...