Unfortunately, there is no clear answer.
Many people and tax professionals think almost all rentals rise to the level of a "trade or business", and therefore qualify for QBI.
Personally, I think when the IRS set the 250 "safe harbor", they gave their viewpoint of the amount of activity that would make a rental rise to the level of a "trade or business". The IRS says that 250 hours would be "safe" (they wouldn't question it, if you also meet the other requirements), but that means less than 250 hours might be unsafe and questionable. While a rental can certainly qualify for QBI at less than 250 hours, in my OPINION, the farther away you are from 250 hours the more unlikely that the IRS would view it as qualifying for QBI.
But both viewpoints/sides are arguable and have some merit.
