When I active the lullaby feature with online radio or Spotify the volume increases too full level regardless of turning it down.
I.e. I select Spotify and have it turned to about 20% loudness. I leave the phone on my bedside. Suddenly 30 sec later it goddess to ful volume. I turn out down and 30sec later again it goes ful volume. Nothing I try keeps the volume at a respectable level!
It drove me nuts and did absolutely nothing to calm me down for going to sleep!
I set levels in the settings to 20% but that did nothing.