I have noticed this. Hulu is definitely the worst with low volume
Issue resolved!! If you have a PC/Mac/Macbook with the iTunes app downloaded, go to the top left tab Account>Family Purchases> to the right side of the page select Movies> hover over the purchased title and select the “X” to hide. Be sure to restart the Apple TV device. This removes the duplicate item from showing in your library.
I wish this was a thing and i didnt have to use Movies Anywhere to accomplish this.