Hello!
Thank you for playing Cinderella Phenomenon. We don't have a proper explanation for what caused this unless you have deleted yoursave files by going through the folders or clicking the "X". If you didn't, there's a possibility that you can easily skip the dialogue you have already read by clicking the skip button that should not be faded. If it still is, kindly open settings. Click "All" under Skip section. It should skip all lines you have read and haven't read. It will definitely stop at the choice menus. Unless you also clicked "Skip" under After Choices in settings, you can click the skip button again until you reach the last scene you've read. Let us know if the problem persists.