When I try to add a Dictation type with German language preference, everything appears in German for me I do not see a mixture although I do on image pairing for example. I am using Moodle 3.9 with the new standard plugins. I updated the content types through the admin page recently so it should most recent versions of all the libraries. Which version are you using?
The reason that there are mixtures of stings is that the lang files are found in the content types or the libraries that are used by the content type. Each library has its own set of strings and language files. Evidently some of the libraries installed are missing the German file on your system. You might try running the cron task to see if it updates them if you are on 3.9.
The reason that there are mixtures of stings is that the lang files are found in the content types or the libraries that are used by the content type. Each library has its own set of strings and language files. Evidently some of the libraries installed are missing the German file on your system. You might try running the cron task to see if it updates them if you are on 3.9.