The cure bug is unrelated to not running a "full build". The cure bug was more likely due to change relating to the system behind the skills in that game.
This is what was related:
The effect duration of the white mage ability Divine Caress has been increased from 1 minute to 3 minutes.
If you don't know what Divine Caress is off hand: "If the next spell you cast cures a status ailment, your target will gain enhanced resistance to that ailment."
So it's pretty obvious why Cure on enemies got bugged lol.
