one of the common pitfall of our animation system.
setAnim sets the animation speed to 1.
so you need to do this :
channel.setAnim(“Walk”);
channel.setSpeed(0.01f);
com.​jme3.​animation.​AnimChannel
public void setSpeed(float speed)
Parameters:
speed - Set the speed of the animation channel. The speed is a scale value starting from 0.0, at 1.0 the animation will play at its default speed.