Is there some buff that interferes with douse?

I was at ERG using both Douse and elemental resistance potion to get my fire resistance up. I used Amalgamate to see the value. It seems that Douse had no effect. After leaving the group must of my buffs dropped, with only the potion still in effect. At that point Douse was working.

Is it possible that some other buff kept douse from working?