slayer's "headsman" ascendancy works incorrectly

While playing slayer with "headsman" ascendancy I noticed that I clearly regularly hit foes with less than 5%hp with my attack skill. I tried swapping my weapon, changing my attack skill, re-learning "headsman" ascendacy node. None of it helped. It still does not work.




Upd: Im terribly sorry that was not a bug at all, only my own unawereness of the modifier on my gloves that literally said "Your hits can only kill frozen enemies"(unique gloves "southbound"), so i guess it overrode headsman's perk.