Unwanted behavior with joystick

Hi guys, I'm facing unwanted behavior with my character.

This is the context : I use a virtual joystick to move the character controller of my main character.
The input value 0 is the center and varies up to 1 to the ends which is what I need and what I give to the Animator to change animations. Speed = 0 -> Idle , Speed > 0 -> Walk and Speed > 0.5 -> Run. Yet, when the player want to go to the opposite direction, he passes through the center of the joystick which gives the value "0" to the Animator for a short period of time but enough to starts "walk animation" and then "run animation" again wich causes a problem of limp to my character.

Do you have any idea in order to avoid this problem ?

Thank you in advance !