Hybrid disengagement doesn't respect brake deadzone

I've got ancient G920 pedals the brake sometimes registers inputs even when not depressed. For this reason i use a deadzone of 10 on the brake in all racing games. This seems to work fine in this game as far as braking goes, except in the Rally 1 cars, the hybrid boost seems to be cancelled out even when I have my foot resting on the brake pedal (with 10 deadzone). Could this be a bug, the game cancelling the hybrid even though the brake is technially not engaged with a 10 deadzone?