Pyre Golem "Bone Kindling" does not consume more than one skeleton at a time

Using that keystone my golem usually consumed all skelies (normals and mages) if they get caught in the explosion. Now I tested static and only consumes one skelie of all 11 (4 mages and 7 normal skeletons) It happened just by playing, I dont remember if it was after upgrading equipment with plus to habilities.
Should I restart my golem? I am level 84 with 31 levels on golem.
Thanks for support and for this great game.