"Product Manager" is a title that means different things to different companies, ranging from mini-CEO to Jira-monkey, and everywhere in between. You are absolutely correct to be talking to many different people to understand this slice of the industry.

I'd ask them what PMs do in their organization, what POs do, and what the difference is in their mind. Ask what level of detail they operate at, what they delegate to others, and what types of things are expected to be passed up to their boss.

You also might get interesting perspectives if you explore outside the software industry. Product managers exist in all kinds of companies, with the same overall goal to understand the market and produce the correct product under the correct business model. But the day-to-day of a software PM is vastly different than the day-to-day of a PM that produces retail goods, for example.