Function keys not working

For some unknown reason, the function keys suddenly stopped working. Either they don't do what they're supposed to (F10 ends the game instead of quitting the program, for example) or they don't work at all. They were working fine one day and the next they weren't. This is happening with Chocolate-Doom and GZDoom, which, to my knowledge, don't allow you to rebind function keys, so that's not the problem. Any help getting them back to normal would be appreciated.

Do they work the same outside of Doom?

Is there a FLock key on your keyboard?

Ah, I can't believe it was that simple. Thanks.