On my S21, the speaker volume is stuck on max. Unless I have headphones or another speaker, the music is blasted at full volume and can't be turned down. I tried closing the app, deleting it, playing with the EQ, nothing seems to work. The volume is fine on every other app except this one. The issue is solved when you connect and disconnect another bluetooth device but as soon as the next song starts playing, the volume is back at 100. Makes the app practically unusable