How do I use custom movement behavior with platform behavior?

I've got a player sprite that accelerates up when the screen is touched and held, using Custom movement. When you lift your finger, it should stop accelerating and fall back down. For gravity, I added Platform behavior with disabled controls.

However, when I lift my finger, the sprite doesn't fall back down. It just keeps accelerating up.

How do I get the sprite to slow its ascent and fall back down when you stop touching the screen?

Here's the project:

drive.google.com/file/d/1u2KclAXYroI-UShNy2IOT4UhnwtC5ZEE/view