After an update in the past that adjusted the friction of all grenades in general the UGL Smoke Grenades became extremely bouncy.
Even when shooting against terrain to stop them they will bounce off into completely random directions flying crazy distances.
This makes them completely inaccurate and ineffective, it is nearly impossible to fire a wall of 3-4 smoke 200m infront of you using the UGL.
Not even to speak of marking enemy positions with smoke, unless manage to hit the smoke grenade inside a building or something of that sort it will fly several hundred meters off target.