CJ4 - climbing in FLC mode often stops climb too early

[moeSizlak]

Very often when on initial climb in FLC mode (at 240 knots constant speed), the plane will just stop climbing and level off. For example If I have 43,000 ft selected, and I'm in FLC mode climbing at 240 knots, it will level off at like 21,000 ft and will start picking up excessive speed. No matter what I do I can't get FLC mode to work again. This happens very frequently.