I heard that DNS over HTTPS will soon be the default for many. In version Firefox 69 I tried it, checking the box under general, networking. On https://www.cloudflare.com/ssl/encrypted-sni/ it works but warns you do not have DNSSEC, and suggests you change the default for network.trr.mode from 2 to 3 which means force DNS over HTTPS with no fallback. When I set network.trr.mode to 3, no web pages load. I increased network.trr.request-timeout but that did not work.
Is there already a bugzilla report filed?