Destroyer shield instantly goes down while still ADS

When im in a gun fight and i want to pull my destroyer shield up quickly, it goes down the second i pull it out. it is very frustrating when it happens because it goes on cool down and the enemy just mows me down. the way to replicate this is hold ADS-->shield. in the middle of a fight it is hard to remember to let go of ADS so most gun fights i die. https://www.reddit.com/user/babafett99/comments/1tudcp2/destroyer_shield_issue/