Great details; thanks!

> Hmm…do you have the in-browser DNS over HTTPS resolver enabled? I personally can't reproduce this, but I'm using DoH with 1.1.1.1.

Yes, using DoH and Cloudflare (1.1.1.1). Have also tried it with 1.1.1.1 turned off; no differences.

As for the other suggestions, my results were the same with Firefox on both macOS and Fedora Linux:

- https://tls-ech.dev - EncryptedClientHello works on first try.

- https://http3.is - HTTP/3 works on second or third soft refresh.

- https://cloudflare-quic.com - (This is the one I reported initially) Stays at HTTP/2 despite numerous refreshes, soft or hard.