Fedora on Dell XPS 13: restoring the function keys

I always wonder what happened when I loose my function keys (volume up/down, pause, forward, backward, etc) and have to specifically type the Fn key to get them to work.

It turns out this is probably not due to my distro upgrade but a mistype somewhere: I found on this bug¹ that typing Fn + ESC swaps the lock of the Fn keys (i.e whether you can just press them or have to use the Fn toggle).

I am now going to try and revert the mnemonics of the last 6 months without it, and hope it helps someone make it quicker.