Swap the cable to another device to see if the cable or device is faulty. Inspect the HDMI for frays or exposed wires; braided cables resist damage better.

To detect a second monitor manually on Windows 10, use these steps: Open Settings. Click on System. Click the Detect button to connect to the external monitor under the "Multiple displays" section.

To answer your question about motion clarity: On the main menu, go to Picture Settings, down to Advanced Settings, and then ...