Cutscene lag problem

So I have a problem. Every cutscene that runs on my pc always lags along with the static audio. When the cutscene battle with cocolia, it ran very smoothly. But since the update to version 1.2, the cutscenes started lagging. Until finally when the update version 1.5, I tried to reinstall the game, and fortunately it fixed. But when I updated to 2.0, it was starting to lag again. I tried to do the same thing by reinstalling it but it still didn't change. Does anyone know how to fix this?? My internet is fine too... Please help :(