I have the perk unlocked and I've tried everything from un-equipping it, storing it in the vault and passing it back from my sub character and it still wont activate the extra chaining so am I the only unlucky Hunter cause I get smashed by other Arcbolt grenades so I doubt there is a equipment problem and like I just said i already purchase Improved Arcbolt Grenade and went on to the second last upgrade defense perk.