[Bug] Mastery missing

Upon using the race change tool in the character selection screen (Human Mage ---> Night elf Mage) my Mastery skill has disappeared from the spellbook.

It now says "See your trainer!".
The mage trainers, however, do not have Mastery for me to learn.

[Edit] - The trainers show Mastery as already learned, but it's actually missing from both the Spellbook and the Talent trees overview.


Thanks in advance.