There are only a couple of variables I can think of. I do not know OP's Blue Magic Skill, as that could be a factor in whether or not the spell overwrites regular Haste. I'm capped with merits, and I have several pieces of Blue Magic + skill gear. I also don't know if Ionis can do something to Haste (very unlikely, but again, I don't know).

The only other thing I can think of, and this is a stretch (it happened to me at first) is that I didn't update all of my Haste macros to replace Animating Wail (which is still equipped for Dual Wield), and when I use that macro, I use Wail instead. I have Diffusion set to switch to a different macro page, and I didn't originally update that Haste macro :/