Why are the sounds playing when I am not even adjusting volume for that specific sound – DrumKnee 3D Drums - Drum set Review

Why are different sounds playing if I am not adjusting volume for a particular drum or cymbals? For example, I adjust the volume on the snare drum and I hear the hi hat, adjust kick volume and I hear a tom, etc etc please fix this bug I actually love this app cause I can play to my heart’s content(or until my phone battery dies)
Review by Yahirtgm on DrumKnee 3D Drums - Drum set.