Mac Pro 5,1 with Mojave 10.14.6 AirPlay Screen Mirror to Apple TV 4K
I have an older Mac Pro 5,1 that I upgraded with a Radeon RX 580 running Mojave 10.14.6. I see the mirroring options in the menu bar, it shows my "living room" Apple TV, I can select it, the icon is blue, but nothing shows on the living room screen (the output device is a newer 1080p ViewSonic projector). The output is black or blank. When I hit the menu button on the remote, it returns me to the ATV home screen. What am I doing wrong?
Mac Pro