TeXstudio is connected to Languagetool, but does not show errors

Question

I've downloaded and set up LanguageTool to connect to TeXstudio like this:

LanguageTool is starting when I start TeXstudio and, according to the icon, connected:

Additionally, I'm able to manually perform a check using my browser. For instance by opening:

http://localhost:8081/v2/check?text=W%C3%A4hrend%20Sie%20das%20Ganze%20mir%20einem%20Holzl%C3%B6ffel%20oder%20einem%20Paar%20St%C3%A4bchen%20r%C3%BChren.&language=auto

However, these problems are not shown in the TeXstudio editor itself:

According to Finding errors using n-gram data, LT should highlight the word "mir" here. (The issue is not related to n-grams, other problems also don't show up.)

As suggested in Problems Installing Language Tool in TexStudio, I also tried the same thing with LT-3.5, but still face the same problem. (Errors are not highlighted)

If you do not know the answer to the problem, could you suggest steps to debug? (E.g. where to find TeXstudios log files, if there are any)

Answer 1

As it turns out, this issue is related to the selected language, where "de_DE_frami" is not a valid option. After installing another version of the German spell checking dictionary (via sudo apt install hunspell-de-de) and selecting it in the options, LanguageTool now highlights the errors correctly.