Yes. Passive income can initially take work to build the income source. Most people consider rent to be passive income, yet people don't just magically own houses, they more often than not work to buy them.
That cut of the rent ends up being around all of the cash flow for a newly bought property, and in many markets ends up being more than the initial cash flow. It’s a second job with irregular on-call.
Well, then you've leveraged too highly. Estate agents here take a fairly small percentage of the rent to manage all of this, so it takes a fairly small deposit before your rental income less management fees can't cover the remaining mortgage.
Repairs, collections, advertising, evictions, etc.