Monstrosity: "Breath Damage +" Instincts don't increase breath damage.

Platform: Windows
ISP: AT&T
Type of Internet Connection: DSL
Date & Time: Nov. 21, 2014 6:30 CST
Frequency: Always
Race: Mithra (Monstrosity Manticore)
World: Shiva
Main Job: RDM
Support Job: BLM
Area and Coordinates: Eastern Altepa Desert, Buburimu Peninsula (Everywhere)
Party or Solo: Solo Monstrosity
Monster Name: Any
Steps:

Equipping Manticore Instinct I (+20% Breath Damage) and/or Crawler Instinct III (+10% Breath Damage) doesn't seem to do anything for breath attacks.

Playing as a Manticore at level 30 with no instincts, Heat Breath does 299 damage with full HP to a variety of enemies. Equipping Manticore Instinct I and Crawler Instinct III for +30% breath damage doesn't add anything to Heat Breath (Still 299).

At level 60 Manticore Heat Breath does 599 damage with no instincts equipped. Again, adding Breath Damage+ instincts doesn't seem to increase this number as expected; it stays at 599. Perhaps maximum breath damage is capped based on this monster's current level, but shouldn't "Breath Damage +" do something?

I've observed similar results with other monsters that have breath attacks, so I'm just guessing that these instincts aren't functioning as they should, or they're applied before some kind of level-based breath damage cap that causes them to have no discernible effect.