No, this is definitely not a language confusion problem. Google translate has long been able to properly separate and translate this.
In my case, I checked it without even logging into the forum. In this case, only 1 language is used in the interface and content. And my interface language here is English.
Surprisingly, when I created this thread, I checked all the translation methods here and on forum.ghost.org. The translation did not work either there or here. Now I have checked forum.ghost.org again and the translation was possible with the help of the official plugin and with the help of the translator built into Chrome. Translation via google.translate.com also does not work. I try this site and the translation works unpredictably (the official plugin translates some pages and some not).
One could blame the problems on unstable work
Google Translator API, but the inability to translate many Discourse sites for a long time suggests otherwise.