No sound and can’t exit the app on iPhone – Love Live!School idol festival Review

I love this game.I am revisiting it after a year, but I can’t get any sound to come out of it even one other sound is coming from other apps. I also can’t exit the app without closing my phone an opening at it quickly swiping up?? I used to play this phone on android and had no problem. I guess it’s just my iPhone. Maybe this is more of a negative review for iPhone. I’m going to change it to five stars, but I literally can’t get this app to work.
Review by かわいそうな方 on Love Live!School idol festival.