Use user language if there's a mismatch

server/vbv_lernwelt/importer/services.py

@@ -837,6 +837,10 @@ def create_or_update_trainer(course: Course, data: Dict[str, Any], language="de"
     user.language = data["Sprache"]
     user.save()
 
+    # As the is never set this is the only way to determine the correct course
+    if user.language != language:
+        language = user.language
+
     group = data["Klasse"].strip()
 
     # general expert handling