The Poet's Pen

Recently tried to get this item to work. Can't seem to get it to proc while casting spells only via basic attack. Is this intended or a bug? May sound like stupid question but it is hard to tell from the wording on the item.

Any help would be much appreciated :)

That's no bug.
It says trigger on attack.
Spells are no attacks.

So only frenzy, barrage, kinetic blast and other attacks for wands will work.

I tried to use poet's pen to launch remote mines with arc. I attack with kinetic blast (6L on chest amour).
Everything works right if i just use arc on the poet's pen, but NOT if I combine arc+remote mine on the pen : nothing is dropped on the ground, nothing to detonate.

Is that intentionnal or is it just a bug ? Is there some timing to respect (casting time of the gem on pen lower than the attack rate ?) or any other tweak not mentioned in the description ?