Turn off DoH, Firefox
I simply don't like DoH because I use a DNS provider that I have chosen - OpenDNS - specifically because they log my DNS queries and let me see that log. I don't mind DNS lookups from my network being logged, as long as the provider does accurate, uncensored DNS lookups. It's helped me find domains to block such as tracking domains used by IoT devices that I can't configure myself.I have my router directing all DNS traffic to OpenDNS so these devices can't pick their own servers, any outbound requests on port 53 will be redirected. If they start using DoH/DoT, I can't do that so easily. I'd have to start monitoring outbound traffic and do hostname resolution on the IPs.I think the privacy argument for DoH in the browser is fairly weak, since doing a DNS lookup is not really an indication of, well, anything really. No matter what domain it was, there's no indication that the user intended to visit a website or use a service on that domain, it could be as simple as a lookup to load an embedded image in a spam email. The only good usage of it is to prevent censorship via DNS.