Floodlight Cam Plus - motion activated light not working

I have 2x Floodlight Cam Plus.The option to have motion detected by the camera to turn the lights on does not work.The lights only come on with the PIR sensor but the "motion-activated lights" options states that camera motion should toggle the lights.Is this a known fault or perhaps im just doing something wrong?I would like to be able to turn off the PIR and have camera motion within the camera zones determine the light activation