F14 and F15 change display brightness even if I turn off the keyboard shortcut

I eventually found out that another app (BetterDisplay) had also assigned F14 and F15 to display brightness control. I disabled the keyboard shortcut in the BetterDisplay app and I was able to regain use of F14/F15 for my other apps.

This is a possible solution to the problem described at: https://discussions.apple.com/thread/253836891?login=true&sortBy=rank&page=2

I wasn't able to reply to the above thread because it's locked due to inactivity.

Hope this information helps someone else!