In fairness, it seems the problem in your case is that the "manager" has built up walls between people, trying to own the work, and in that not allowing you the full context that would allow you to make informed decisions around such asks. "The manager not wanting you to spend time debugging this now" should be a false premise. Knock down the walls and you will know yourself that you shouldn't spend time debugging it now.
That makes sense. Either knock down the walls all the way and empower developers to make decisions, or keep the walls and let all requests go through the pipeline.
