Hexes are auto-triggering/draining my hex removal spells?

I can't figure out what's going on.

I have the following hex removal skills on my skill bar:

Remove Hex - Remove a hex from target ally.
Divert Hexes {E} - Remove up to 1...3 Hexes from target ally. For each Hex removed in this way, that ally loses one Condition and gains 15...63 Health


I keep getting hexed by Graven Monoliths with the following hexes:

Clumsiness - For 4...7 seconds, the next time target foe attempts to attack, the attack is interrupted and target foe suffers 10...76 damage.
Crippling Anguish - For 8...18 seconds, target moves 50% slower and suffers -1...3 health degeneration.
Conjure Phatasm - For 2...12 seconds, target foe experiences -5 Health degeneration.


The problem I'm having is that one or all of the hexes are auto-triggering my Divert Hexes spell. When this happens, the spell is ineffectual and has to recharge. The effect is that I can't remove hexes with this spell until it recharges. By that time I usually die. Oddly enough, my Remove Hex spell is not affected in a similar way (but this lone skill isn't robust enough to keep me alive).

I've read the skill descriptions for all of the hexes I listed (copied and pasted above). These descriptions say nothing about draining or auto-triggering hex removal skills.

Is something wrong? Or are the wiki descriptions of the hexes incomplete? Is there anyway to prevent or counter this occurrence?

Thank you!

Anna