F Keys

[Kirika-]

To add, sometimes laptops due to their size, have a "smaller" keyboard layout, as in not enough physical keys for all of the normal keyboard functions, and as such the Fn keys might be dual purposed keys.
As in, there may be a dedicated key that must be pressed to toggle between a given Fn key's functions.
So maybe there is a key on the keyboard that needs to be pressed with the Fn key in question to switch to the F1 function and off of the function that is effecting the full screen display of the game.