They were bugged and doing 2x the armour pen they were meant to.
Also the stacks they put up were buffing the demolition round/heatseeking missile attack by 50% instead of 25%. Also counted every other armour debuff from any other class as a buff as well so it could ramp up the damage to ridiculous levels.
So that was corrected.
Then Grav/Tracer was nerfed in damage by 10% for good measure.
That's what happened to grav/tracer spam.
Actually the damage was nerfed, THEN they fixed the stacking vortices buff issue which completely negated the "damage rebalancing" that was supposed to happen for DR to balance out that damage nerf. THEN they nerfed armor breaks stacking.
Then they buffed smash, because why SHOULDN'T a class be able to have an autocrit super buffed armor penetrating AoE.