Khan Academy bug on quizzes and unit tests

I have been using khan academy for a while now and recently I’ve noticed on this new update that the quizzes and unit tests are automatically marked complete as soon as the student completes the exercises before it. This isn’t exactly the most convenient as now the students are using it as a shortcut and are missing the learning. Ideally, users should have to complete the quizzes/unit tests by themselves instead of the platform marking it complete for no reason. Does anybody know how to fix this issue?