I'm having this problem for a while now and I would like to know if there is a fix for this.
My libraries for Styles, Swatches, Gradients and Brushes are being duplicated over time. My fix is to delete those duplicates when there are too many. Somehow CC is creating a folder like "Styles from computernamehere.local" over and over, same for swatches or brushes. Since I have two computers, it will create a few for each computer.
In the images below you can see what happens. I have three samples, and then 4 folders. On top of my original stuff there are three folders that are a copy of my stuff, two from one of my computers (07) and then another one (01), inside they have the materials duplicated.
This happens not only with Styles but also with Swatches and Brushes. In fact today I got a notification that Photoshop wasn't able to load more brushes because there were too many. Of course there were a lot of copies I didn't think of. I periodically delete those but it shouldn't happen in the first place.