Honestly, it may have nothing to do with the browser.
For instance at&t's newest fiber gateway (bgw320-500/505, 3-4 years old at this point) has a known issue that bypasses pihole for all Wi-Fi devices. Such that only hardwired devices can utilize its DNS services. Even with the pihole acting as DHCP server
It could just have enabled DNS over HTTPS in the settings, hence not having used the user set up DNS at all.
Except for getting the IP of the DNS that they then connected via HTTPS.
Librewolf uses Quad9 by default IIRC.
Waterfox bypassed my ad blocking DNS and served me ads. I uninstalled it, not gonna try it again until they get serious about privacy.
I think they're talking about pihole not ubo
Honestly, it may have nothing to do with the browser.
For instance at&t's newest fiber gateway (bgw320-500/505, 3-4 years old at this point) has a known issue that bypasses pihole for all Wi-Fi devices. Such that only hardwired devices can utilize its DNS services. Even with the pihole acting as DHCP server
It could just have enabled DNS over HTTPS in the settings, hence not having used the user set up DNS at all.
Except for getting the IP of the DNS that they then connected via HTTPS.
Librewolf uses Quad9 by default IIRC.
they're doing that with dns over https, which is secured against your attempts to avoid corporate tracking. look for a doh blocklist.