No video when playing movies or TV shows downloaded from iTunes on new 2019 iMac

Brand new iMac (Retina 5K, 27-inch, 2019)

macOS up to date: Catalina v10.15.2

When I try to play Movies and TV shows that were purchased from iTunes on the iMac via the Apple TV app, I hear the audio but only see a black window--there is no video.

If I try to play them with QuickTime Player, I get the following message:

This Movie cannot be played because it is on a display that is not authorized to play protected movies.

Try moving this window to a different display or disconnecting any displays that are not HDCP authorized.

I do not have any additional displays attached to this machine. I have tried logging out of and back into my Apple account, I have re-downloaded the content, double-checked to ensure the computer is authorized and I have unplugged my OWC Thunderbolt 3 Dock.

Does this mean the iMac is not HDCP compliant?