I don't think the 4.89 will matter, that is still a respectable number and not a true reflection of the property if it was for value......being dinged for cleanliness would be a proplem. Looking at your area, the price per night for your property is many times what other houses are going for. I bet this is a pricing issue not a rating or write up issue. The pictures are good. The write up talks a lot about what has been done to the property rather than how the guests will enjoy it but I doubt that is holding back the property for booking volume. I always say, I'd rather be booked constantly at a lower price than only periodically at a higher price. Consider lowering the price to be more competitive for your area.
Hope this helps, Scott O