Overlapping music in iOS video ads

When video advertisements are distributed on iOS, the original music of the game is overwhelmed by the music of the video advertisements, and the frame rate of the music slows down and becomes covered with noise. Even after the ad delivery ends, the game music is still muted. In my environment, it occurs when a Chartboost ad is served. How can this be avoided? There seems to be no particular problem with video advertisements of other companies