Trying to understand how PM teams handle conversion drop-off what's your process?

Honest question: when users drop off your funnel, how does your team actually figure out why? Not looking for tool recommendations, I mean the actual human process that happens after you see a drop. Like, does someone own this? Does it go to analytics, PM, growth? How long does it usually take before you have a reason you're confident in? Asking because I'm trying to understand how different teams handle this. A few things I'm curious about: