thats because you dident set the animation, to have same speed, when you open up you charachter animation in the c2 editor, each frame has a speed amount, and the animation has a repeat count, or speed animation play, if you have 12 frames in the animation you should play the animation at 24 frames per second, that will make it look natural, if you crouch animation is longer then 5 frames, then for each frame of the crouch you should make it so last 0.25 or 0.5 seconds, that will mean each frame of the crouch animation has to be 0.05 or 0.1 if you have the jump animation frames included in same animation
or you could call the jump condition to happen if you have diferent animation lets say, you have crouch, and jump animation to trigger
now when you press the jump button the first animation you want to play is the crouch
so the code should be calling : when spacebar pressed set animation crouch, if frame is last frame in the crouch animation, set animation to jump , if frame is the 1st in the animation jump then trigger jump behavior! thats a easyer way to do it!
if falling set animation to falling.
if landed set animation to idle
if player moves left or right set animation to the keys it moves (left right)