Guild Wars 2

Signet of Stone Question
Signet of Stone states that it’s Active Effect causes your pet (and you with Signet of the Beastmaster) to takes no damage for 6 seconds. While it prevents any initial damage from an attack during those 6 seconds, if the attack applies a DoT of any kind, the DoT does indeed deal damage.

My question is, is this it’s intended function? Should it prevent the application of DoT’s during those 6 seconds as well?

Signet of the Wild Question
Signet of the Wild states that it’s Active Effect causes your pet (and you with Signet of the Beastmaster) to gain Stability, along with growing larger and dealing more damage. Now Stability is supposed to prevent all control effects. It doesn’t, at all. Rampage as One also grants Stability, and the same applies. I have been knocked down, knocked back, pulled, dazed, feared, and stunned while having Stability on myself.

So the question here is, is this a known bug?