The Greater Armour of the Vigilant Watcher is supposed to bestow the wearer with 5% extra critical healing chance.

I've experimented for hours with multiple armour sets and builds and my healing crit percentage hovers around 50% +/- 2% regardless of if I'm wearing this set or not.
I've concluded that the armour set bonus does NOT work at all.

Can anyone else confirm this as well?

If it is indeed broken, please fix this problem.