Replacing "search" key no longer works

Prior to an OS update, I was replacing the "search" key on my apple keyboard (F4) with Launchpad. It seems that I can no longer replace any of the default function keys with different functions. The key recorder does not recognize any of those key presses any longer. Thoughts on how to fix the issue?

Nevermind - SecureInput was blocking it because I had a webpage with the login window up.