When you set the limits on "Smart Pricing", Airbnb provided you a graph suggesting the upper/lower prices.If your lowest price set is mainly above the lower limit suggested, Smart Pricing will use that price, as their is (according the Airbnb algorithms) no reason to set higher prices.
@Judy522 "smart" pricing is not very smart, and is well-known to underprice. (Airbnb has a conflict of interest here. If they can get you to lower your price, they can raise their own guest service fees without raising the total amount the guest pays.) There are several independent automatic pricing utilities out there. I've had great results with usewheelhouse.com.