Just happened today. Appears to have cracked at the 'belly button' point. I've contacted customer support at Andersen hitch. I've also broken many lego blocks.
Got my set and have used them 4 times. No problems and love the way they level. Hope I don't crack mine, but if I do, it's nice to know that Customer Service will take care of you.
Bet they add a little more mass to their design soon so they don't end up having to replace a bunch of these.