I only see HDMI screens and not HDCP.
I receive a similar error via Display Port from my GTX Titan Black and my Display Port only ROG Swift PG278Q ‑ 27″ LED QHD Monitor.
Check under you GPU control panel
For Nvidia it will be listed under
Display/view HDCP status
I don’t own an AMD card so can not advise on that.
See if your graphics card and display are showing as HDCP-capable.