I am jumping in here as is out of office for the day.One simple way to further isolate the issue to a faulty monitor would be to connect it to a computer that is HDCP compliant and check if the display is 1080p. However, does the lack of HDCP mean that some of the movies or programing from my DVD player or HD Directv receiver will not appear on the projector? You might not like this option but it works without any issue. Catch the Tom's Hardware Show at 3PM Eastern on September 23! Now I'm sure if the Intel HD 530 graphics is HDCP compliant, thanks to your info. You have to make sure that your monitor is HDCP compliant and that it is the only monitor that is connected to your Mac device.
Enable HDCP protected content playback on macOS (iTunes) I had to downgrade to Sierra 10.12.6 because of the multi-monitor incompatibility of Displaylink 10.13.4.
