mac mini 2014 viewsonic pjd7820hd
Hello. I am installing a 2014 Mac Mini as a home entertainment system, with video to my Viewsonic PJD7820HD projector. All seems to be working, except for video playback from the Apple TV app. Video from the Apple TV app appears only a black screen with the audio playing. I do see the video playback controls. Only the Apple TV app video playback window is black; the rest of the screen functions normally while the video plays. Video plays as expected when I attach the Mac Mini to a desktop monitor, and other kinds of video such as YouTube clips work. The Mini is running Catalina 10.15.7. I am signed in to my Apple ID account and have the computer authorized. I believe I have all the display options in System Preferences set normally, although perhaps there is a trick I am missing?
Many thanks in advance.
Mac mini, macOS 10.15