Do you mean your left stick (rudder left / rudder right) inputs are slow to move the helicopter nose? But your pitch collective elevator and aileron inputs react normally on the helicopter?
I got this bit of info on proper binding from HF:
Make sure that the throttle hold switch is to the back selection 0. Make sure channe 5 knob is turn all the way clockwise and the rate swtch is on high. Make sure f mode is 0.
Make sure only dip switch 4 is up all others down. Make sure all trims are 0 and throttle is all the way down.
Plug battery into the 120sr. Wait for the red light to blink.
When it starts blinking, hold the trainer switch towards you. Turn on power. After 2 or 3 beeps and the red light on the Tx stops blinking release trainer switch. 120sr should bind in a few seconds.