Look for an "Fn Lock" icon (often on the Esc key). Press Fn + Esc to unlock the F-keys and try again.
He checked the basics: . On his Dell laptop, the F10 key doubled as a “Mute” button. He tapped Fn + Esc to toggle the lock. Then, Shift + F10 again.
“Sometimes,” he’d say, “the button is just a suggestion.”