Shot metre continuing despite letting go of the X button? Fix?

Im experiencing an issue where as the title suggests, I hold down the shot button to time the release, yet whdn I let go it continues, bricking the shot. I've checked and the button does not seem to be sticking, and even checked on other games and it still presses fine. If I shot with the shot stick, after a couple of minutes, it returns to normal ... for a minute.