Ask HN: What questions do you ask to improve clarity on vague requirements?

I recently worked on a ticket that was quite ambiguous. It felt like "we saw this thing once that hasn't happened since, and we think there might be a bug in there, so see what you can do to fix it, and we don't understand that code any better than you do". I have to actively fight the tendency to go down ratholes of learning & curiosity, and it was quite difficult to keep the scope of this ticket from exploding, and it's still open. But it does compete for time with newer priorities as they come up.

One question I've learned to ask is:

- Given a lack of more specific requirements, what behavior are we expecting to see vs what we are actually seeing?

- How should I prioritize this ticket relative to the other tickets in my queue?