SetFloat not working correctly?

Hi there, beginner here to vfx graph. I'm trying to set an exposed parameter via script , but nothing seems to happen in game. I have a print statement that lets me know the value of the float I just set, but I don't see it referenced in game at all. Any ideas? My code is below.

The Graph


The Code

VisualEffect vfx = whipPS.GetComponentInChildren<VisualEffect>();

vfx.SetFloat("lifeTime", 1);

MonoBehaviour.print(vfx.GetFloat("lifeTime"));

Inspector(nested in a prefab that gets instantiated on the parent gameobject when the mode starts)