Now and then the Windows Start Menu Search or the common simple name of Windows Search something doesn’t work after starting up or suddenly during the day. In older Windows it was the Explorer that was not responding anymore. But in newer Windows. Windows 10 and Windows 11 the Search has it’s on dedicated App.
Open the Task Manager by hitting Ctrl + Shift + Esc. Find the Search App and right click and press “End task”. Don’t worry, the Windows Search process will automatically restart the next time that you search.
If that doesn’t help. I’m afraid it’s back to the old classic. Turn it off and on. Restart your PC device.