Trackpad issue in JW Library

TrackPad won't scroll within the body of a book or other material, in the JW Library app. It won't scroll with the arrow keys either. Why? It will scroll to select a specific chapter of a book to review. So far, haven't had issues in any other app. Prior to having this MacBook, I hated a track pad, or track ball. Once I purchased this MacBook, I fell in love with this track pad. It is so responsive.