General

Profession Mastery dropping faster than usual

Anybody know the current drop rate for profession mastery?
I'm currently a meister and when I first became a meister, the mastery would drop after every ~18 hours you don't craft.
I would lose 500 mastery exp per hr.
Recently, with the huge inflation of cubic blades and superior crystals, I haven't been making cubes and relied on android hearts.
Yesterday, I made an iron heart and had ~24k mastery and came back today ~24 hours later to see that I'm down to 16k mastery.
I made another iron heart and logged off. Logged back on ~2 hours later to find 14.9k mastery.

So... is mastery dropping after each hour of not crafting? Or does iron hearts not count (Note: I did gain 100 mastery from making the heart).

Thanks in advance