To "unlock" your Dell Fn key:
Keyboard function keys - Inspiron 15 3535 Owner's Manual | Dell US how to unlock fn key on dell laptop
The Fn (Function) key on Dell laptops toggles secondary actions on the keyboard’s top row (e.g., volume, brightness). Users often find the Fn key “locked” in an inverted mode, requiring pressing Fn + F1–F12 to use standard function keys. This paper outlines three primary methods to unlock or reverse the Fn key behavior on Dell systems. To "unlock" your Dell Fn key: Keyboard function