that means that either the item is configured wrong, or your plugins are messing with the engine.
to check both options, please give us a screenshot of the item in the database, and screenshots of your plugin manager listing all plugins and their order.
then we can check for the possible causes.
and the item shows the reason why you got the wrong marker
The plugins you're using most probably default to HP if there is nothing set in the damage formula.
I suggest setting the damage effect to "MP Recover" and use the damage formula instead of the effect window, that should solve your problem.
It makes sense that you try to focus on the squishy mages at the back of the party first, right? If the mage can out-DPS the enemy DPS before the latter can kill the tank in front, the fight becomes boring.
…I think I might need to switch from standard ATK/DEF up/down buffs to parameter altering states. I just had an actor whose usual attack against an enemy does ~25 do a buffed attack against a debuffed enemy for ~600…