Your question is Systematic Code Debugging Approach. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
How do you approach debugging a piece of code? Walk me through how you would reproduce the issue, isolate the failure, use logs or tests, and decide whether to profile performance or inspect correctness first.