All servers.
All names.
Multiple hits can block any other animation (poiton\skill\dodge etc). It works almost like a soft stagger.
Example: perforate hits (they fast, only this reason). Old flamethrower (dunno new one does it or no), blunderbas.
Most of the time default combo from BB: Shrapnel+light attack will block you from dodge roll, so you will not be able to evade extra grenade explosion or can cancel your potion.
P.s. it is the same bug, that was with Flamethrower that cancel potions, but it is global