I am so so sorry =( Thank you so much for playing my game! I will polish it up and fix that volume!
It was my first time adding audio to a UE game, I was having trouble with this sound file so I kept pumping up the volume parameter, then realized the sound file was corrupted. I must have forgotten to reset the parameter back. And to make it worse, my speakers volume was turned down very low, because I was burning midnight oil, didn't want to wake up the family, so it sounded ok when I tested it.
Just so many factors put together :(