Homing grenades are sticking

is it normal that homing grenades sometimes stick to the heads of the enemies and then explode later in a huge overkill, exploding their entire head?
there is no sticky mod on it

Looks like a glitch to me since your item card says Homing, MIRV, and Bouncy.

yea. or maybe its something special for those little skags? they are like catching the grenades with their tongues?
its not happening with human enemies

Skags can catch your grenades, no matter what parts you have on them.