This may not be the fault of ag_UnitFrames, but I figured this is a good place to start.
The XP bar is only showing reputation. I also have FactionsFu installed and it always monitors a faction. In the default Blizzard Reputation UI it has the check mark next to the faction to monitor it. When I toggle monitoring factions in FactionsFu it also toggles this check mark. Also, if I turn this off either through the default UI or FactionsFu, I will see my experience.
So, is this a problem with ag_UnitFrames or with FactionsFu? I haven't found a part in the code of either addon that checks for that flag so I'm not sure how to diagnose this problem.