If you see Input Not Supported Monitor error on your Windows 11/10 PC, you can apply any of the solutions in this post to resolve the issue.

Fix: NVIDIA custom resolution not supported by your display 2] Change the resolution on the Display/Monitor settings This follows if changing the resolution on your Windows 11/10 PC – you can ...

That is how my monitors have always worked. Whether the display is actually 'displaying' the selected input or not, the device connected on that input thinks the display is there and powered on.

The standard analog input for a PC monitor is the Video Graphics Array connection. As technology has developed, many PC monitors have been manufactured accommodate multiple input standards.