Hello, Pete
Welcome to Microsoft Community.
Is there anything unusual showing up in Device Manager? First, make sure your TV is connected properly. Right-click the Start menu icon and open Device Manager. Find "Display adapters" and expand it. Also, check the "Monitors" section. Look for any devices with a yellow exclamation mark or a red X, which indicate a problem. If there is an issue, right-click it and select Properties. Take screenshots of each tab for us to review.
You can also check the Windows Event Log for any related clues:
Right-click the Start menu icon and select Event Viewer.
In the right-hand Actions panel, click Create Custom View. In the pop-up window, set the time range when the issue occurred. These events might not always be errors or warnings; they could be informational events too.
In the filtered logs, find the relevant events and double-click to view the details. The details include the event source, event ID, and description, which can help diagnose the problem.
If you need further assistance, feel free to share the specific event log details with us for a more accurate analysis.
Yuhao L
Microsoft Community Technical Support
