When enabled, previous items become locked immediately after you move to the next item or when the 60-second timer expires. The score is only updated after an item is committed by clicking Next, when the timer expires, or when you submit the exam.

Timer rule: each item has a maximum allowance of 60 seconds. The score is not updated while you are still on the current question. It updates only after you click Next, when time runs out, or when you submit the exam.