Hi, newbie so be kind. Trying to watch AppleTV on big screen from my iphone7 using a lightning to HDMI cable. Can watch progs fine on the phone but as soon as I connect to the TV keep getting the message “video cannot be played while the screen is being recorded” Can play stuff from my picture gallery but it shows only a tiny picture in the middle of the TV screen. Just FYI I’m in Devon in the south west of the UK. Thanks in advance.