Questions being repeated after finishing a system / can't review older material

I have completed the questions on the cardiac system 680, however i continue as I want to go over material to strengthen the memory. I notice the question bank now goes 690+ over the 680 questions as seen below. What’s happening is the same questions are coming up immediately. I tried this yesterday. As soon as I completed the last questions and got to around 680, the same questions keep appearing, even today when I’m looking to revise material. As of now, when I go to revise cardio, i’m getting the same 2-5 questions on reperfussion injury and calf thrombosis continously. Unfortunately I cannot other questions.