We recently purchased a 2017 Pacifica and we are trying to attach our iPhones to the rear screens. I have the lightening to hdmi adapter and the hdmi cord. When I turn the screen on it tells me to select source. We select the hdmi source for the screen we are at but it just continues to tell us to select source. We have been able to get the fire stick to work and can go that way but that would make the kids watching the same thing vs their own movie. Any suggestions. Not sure if I am missing a step.