shattering blow skill tree passive and sunder bad interaction with stuns affects

When you stun a enemy with sunder when you have the passive of shattering blow it is meant to do 50% of that enemy armor and if you have 100% increased armor brake then you and break the enemy's armor every stun but it appears to fail to do this and it does nothing but just stuns the enemy

I have tested this with both scavenged plate that does not apply the effect with any stun that i do with sundar but will apply with other skills and i have tested with break endurances that has not given a endurance charge when i stun with sunder but will work with melee attacks that stun, everything in game that would react to the armor break show that it is not breaking the enemy's armor and reading sunder shows no thing that tell the player that there is something that stop sunder from braking armor thus i believe this is a bug

It also appears that when you stun with other skills it only take exactly 50% of rare mobs armor and does not take any increases into account when it calculates the value for the brake aka : rare mob has 10000 armor when i stun through basic attack it set the brake armor value at 5000 but i have 150% increase armor brake so it brake value should be 12500 armor break