Curse on Hit Bugged on Poet's Pen

This is probably related: I currently have one Poet's Pen equipped (off-hand) with a different wand in my main hand. If a spell (e.g., Frostbolt) is socketed into the Poet's Pen, my character doesn't alternate wands when attacking. My character will switch which hand is the hand that attacks after taking a few steps, but the attacks will only be with one of the wands until I move again. If I have no spells socketed in the Poet's Pen, my character will attack as expected (alternating wands).