RDM "Composure" not increasing duration of self-buff spells in Inner Horutoto.

Platform: Windows
ISP: Comcast
Type of Internet Connection: CATV
Internet Connection Speed: 50Mbps
Date & Time: NOV 4, 2015 09:00 CMT
Frequency: Always
Character Name: Laimeowmeow
Race: Mithra
World: Cerebus
Main Job: RDM, Lv.75
Support Job: BLM
Area and Coordinates: Inner Horutoto Ruins "Beetles Burrow" area.
Party or Solo: Solo w/4 Trusts
NPC Name: None

Steps:
1.When I was in the area I needed to battle monsters from Grounds Tome page 6, I used the "Composure" Job Ability.
2. I then cast self buff spells such as Haste, EnBlizzard(etc), Refresh, Ice Spikes (etc.). The duration of the spells is usually quite long with Composure. Est. 10mins or more.
3.After about 5~6mins many of the buffs wore off a lot sooner than normal with "Composure" job ability even though I always use "Composure" before casting any self buff spells.