In Smart Soothing mode for Bounce or Sound, if you change the level from the sliders on the home screen, the update will stay at the chosen level until your baby changes sleep states.
Note that not all sleep states are displayed on your Home screen. For example, if the baby stirs in sleep, the crib can start light soothing because it classified sleep as ‘light sleep’ rather than ‘deep sleep,’ while your Home screen continues to show ‘Baby has been asleep since 2 hrs’.