Dripleaf continues to make the tilting up sound even when powered.

Powering a Dripleaf plant with a Redstone Torch still plays the titling up sound, even though visually it does not move, when an item or entity is on it. Shown in the video.

How to reproduce:
Place a Dripleaf plant and a Redstone Torch next to it
Stand on it or throw an item onto it
Listen to the sound, subtitles prove this as well.