Stone Charms still not functioning correctly?!

When having a Stone Charm equipped its benefit of not getting stunned doesn't really work. Regularly I am getting soft stunned and my attacks interrupted. And when I am being stunned in a way that the charm is proccing I lose one charm charge but still get soft stunned. And most importantly my attack gets interrupted despite the charm's "effect" of not being able to get stunned.

Please either clarify how the charm is really supposed to work, or fix it in a way that when its effect activates your attacks don't get interrupted. It is very frustrating when your attack gets cancelled despite the charm being activated.