1.1.1.1 for Families doesn't seem to support the canary domain so by default Firefox would bypass this service. Also the canary domain only works if Firefox is

1.1.1.1 for Families doesn't seem to support the canary domain so by default Firefox would bypass this service. Also the canary domain only works if Firefox is not explicitly set to use DoH. If using DoH has explicitly been set by the user than the canary domain has no effect. Edit: Some testing seems to show that Mozilla has lumped these in with a select few others and will not bypass them when DoH is the default instead of explicitly selected even though they don't report the canary domain as an error. It will bypass them when DoH is explicitly enabled.