There was a bug that was causing the Biggs ship to refill its entire protection bar when his team applied a target lock, or when his team attacked and didn't apply a target lock, or seemingly at random when any ship did anything. It was making Biggs nearly invincible in certain setups/matchups.
Presumably the update is meant to fix that so he only regains the amount of protection described in his abilities, and only under the conditions described in his abilities.
It isn't a nerf, a change to the way his ship is supposed to work, or anything like that. It's just a bug fix to eliminate some drastic misbehavior on the part of Biggs' ship.