Desmos platformer

I made a simple platformer in the graph, but there are a few bugs. When you jump, then hold down (holding down freezes the screen) you can jump several times higher than you are supposed to be able to. Also is it possible to make it so that when you hold down you dont freeze the whole game???

It is touchscreen, and to jump just swipe up, and movement is swipe left and right.

Platformer