Skill bug after last update

Before the current update rolled around a few skills were working fine, now, not so much.
I play a gunner so use Parting Shot, Quieting Gale, Bulletproof, Stopping Power, Nature's Favor & Revealing Scope. Problem is this latest update seems to have broken them. The tooltip still says "Avaliable when you equip Dual Pistols/Aethercannon" but attempting to use any of those skills just results in "You must be equipped with an Off-hand weapon to use this skill" But I have specced into Aethercannons over pistols so you can imagine my frustration at this bug, and knowing that it used to work and now for some reason or another doesnt.
What I would like to know is will this be fixed or was it a feature put into the last update because personally its a pretty silly feature if its the latter, whats the point of someone who uses aethercannons unable to put distance between their target and silence them when needs be.