After using an iPhone 6s with my transmitter, it now won't connect to an iPad.

I normally connect my phone to my transmitter to use as a touchscreen monitor when flying. I have recently bough an iPad and would like to use this instead of my phone, but when I connect it and click "camera" on the aircraft, it loads the screen but stays "offline" and everything is greyed out.

How do I add a new device.

P.S. All my flights are in sync between the devices.