Every post has a detected language done by AI.
If you have a post originally written in “Chinese”, by right, the LLM should detect it to be “zh_CN”. You can view the detected language in the regular composer (not the translation composer) next to the 
.
The detected language is important so that the translator does not unnecessarily translate it to the detected language itself, and translates the post to every other language.
I suspect what is happening with https://openttc.com/t/topic/58 is that the detected language is incorrect, can you check?