I'm sure you're not doing anything wrong, but you probably have a lot of competition.
I looked at your listing and the place looks clean and well maintained. You have a good number of excellent reviews, and that helps a lot. The decorative touches are all in tones of brown, however -- maybe you could add a little more color? Your listing description has ALL CAPS for part of it, and that makes people feel that you're shouting. That could make you seem desperate to rent the place. For your profile picture, maybe something showing you outdoors would be more inviting, too.
Once you've made some changes, raise your price. If you have neighbors with the same kind of unit who are charging more, people who are comparing might think there's something wrong with yours since you're charging less.