[2021] Stealth Stumble Nerf?

Just got out of a morning Veteran warmup run. Crushers would not stumble during crush.

Legit dumped a full 3x rounds twice plus 2 more shots from my white TAC14 into the face of a Crusher at point blank while he crushed a teammate: No stumble.

Crushers have 250 sHP, +90 sHPS regen, and a 2.5x stumble modifier. My white TAC14 dealt 116 sDMG per shot, 290 sDMG per shot into the crusher's weakspot (all were hitting the weakspot, point blank w/ sh*tloads of accuracy cards + lazer). I was doing about 325 sDPS with all my reload speed mods.

I should have been stumbling the Crusher every shot during the crush, but in the entire run I was incapable of stumbling the Crusher during the crush; I was able stumble during the crush last night.

Edit: On top of that I was running Shredder and Marked for Death, so in theory I was doing +25% stumble damage (stumble is based on a coefficient of damage, so as damage goes up so does stumble damage).