Your question is Reproducing Elusive Bugs. 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).
Describe a bug that was particularly difficult to reproduce and how you eventually found it. Explain the technical conditions you investigated, how you narrowed the search, and how you communicated progress while the cause remained uncertain. Focus on your individual actions, the evidence you gathered, the final root cause, and what you changed to prevent recurrence.
