Encrypted SNI

[fritex]

Well, it will fail, but may I suggest reading below article as far as ESNI is being replaced by development of a new ECH so far:

Good-bye ESNI, hello ECH!

Encryped SNI test if failing on Firefox

Firefox have moved to a newer version of the draft standard for ESNI, which is now called Encrypted ClientHello. I think Cloudflare are still working on a new implementation, so interoperability is likely to be broken at the moment.

Nevertheless, when I enable ESNI in my Firefox, a lot of Websites do not open either due to my Anti-Virus (ESET NOD32) and similar:

Encryped SNI test if failing on Firefox

If I enable ESNI in FireFox, due to my ESET NOD32, it fails. If I disable one option in my ESET NOD32, then it works. This is also familiar issue, so maybe you have the same thing going on?: Since then, I keep my NOD32 option enabled, and ESNI disabled in FireFox and wait for further development.

In my opinion, I would not worry so much if it fails either nowadays:

Cloudflare Browser Check