Will a fan motor run in reverse if the receptacles polarity is reversed?
Just crappy fan design and misleading ratings (450-920 cfm with no duct at all, and terrible fall off with any normal resistance - or else it's an outright lie.) What is your actual duct arrangement (size, length, number of turns?)

If the fan was running in reverse, the tissue would be blown away, not sucked up from any distance. A/C motors run on current that reverses polarity many times per second, and their direction of operation is not affected by that.

Either return it, or scrap the fan and replace with a quality duct fan designed for range hood service (grease, moisture, heat) - might as well go for quiet as well while you are investing in quality.