Why are some websites unable to translate?

Aaron

Even the translation button in the address bar does not display:

https://www.ribbonsoft.com/doc/qcad/latest/reference/en/

lfisk

@Aaron Interesting site... It will translate for me but I've never seen 3 translate boxes Popup before. Even more interesting is being able to select a different language in each box

QCAD User Reference Manual.jpg

DoctorG

@lfisk Because of the framed content.
A known and confirmed Vivaldi issue,

mib2berlin

@Aaron
Hi, not even Chrome, Edge, Brave can translate this page, I don't think this is a Vivaldi issue.

Cheers, mib

DoctorG

HTML source of page:

<!DOCTYPE html>
<html lang="en-GB">

Page identifies itself as language en-GB.

But Vivaldi's Chromium core can not detect language, it is undefined as i see in vivaldi:translate-internals/#detection-logs