Hi all i have this connected with the included hdmi into a Yamaha 3070 avr and then into my hisense tv. The screen displays but keeps disappearing. I can hear the sound clicks as i navigate menus but nothing on screeen. It comes and goes.
Well first test is always to try to connect the Vero directly to the TV. If that works than you can start looking where the issue comes with the AVR in the chain.
Also swapping cables might also be something to check.
I have the same receiver as you, Yamaha RX-A3070 to which the Vero 4K+ is connected via HDMI and the Yamaha is connected to a 65" Panasonic UHD/4K TV and I haven’t had a problem. Could it be something in the settings causing this?