With a clean install of Fedora with XFCE spin I was running into issues where the mute indicator led would be on, but the audio would still be playing.  After a bit of playing, I determined that if I were to mute the audio with the hardware button, all would behave normally.  However, if I were to press the vol up/down button, the mute led indicator would turn off, but the system would still be muted.  This meant that the led would now be on exactly when it shouldn't be.  I'm running on a Thinkpad T420 and have not tested on other systems.

I found a simple fix.  I simply append "unmute" for the keyboard shortcut entries "XF86AudioLowerVolume" and "XF86AudioRaiseVolume".