I read a few different solutions for fixing the sound toggle on Debian via the command line but the only solution that I could make a keyboard shortcut for was:
Hard unmute Pulse Audio in Debian, Xfce when the sound won’t come back on after muting:
pactl set-sink-mute 0 toggle
To set this as a keyboard shortcut
Open keyboard settings and find Application Shortcuts.
Add new shortcut with the following command:
This was a temporary fix and I will change it to Fn & F10 once I learn how to change the Fn hardcoded keys.