I've had the same issue on my Paladin. I've got Enmity +43. And in the Archer AF Body fight the day after Server merges, someone could walk by the mob I had and it would turn green and walk away. They didn't even have to do anything, just walk past. The same thing happened in the Moogle Primal fight last night. Any of the Non-Gladiator Moogles would drop to green instantly and attack someone else, even directly after a Provoke, or a Flash.