This did fix the error!... but my knockback still isn't working for some reason... Lol.
you are calling move and slide only once (in the knockback function), but you need to call it every frame for it to continuously update
like
func _physics_process(delta): move_and_slide()
Glad that helped. I think SimulatedGravity has your next step. You need to process the action as long as you have velocity to keep it animating. Consider friction or something similar to slow it over time or it will just continue to be blown away.
