2011 rmz250 gear issues

Have a 2011 rmz250 with fairly low hours. When the bike is off and in neutral, if I push the bike or spin the rear tire on the stand it drops into gear on it's own. Sometimes I can hear the gearbox knocking almost like it isn't fully in neutral and other times it sounds clean but suddenly kicks into gear, I do make sure it is in neutral completely but it still does it. I called the dealer and they haven't heard of any problems like this and I haven't really found any info on the internet about it. This is not a false neutral issue and I haven't had it happen when riding, it shifts completely normal in all gears and have never had a false neutral which is why I'm not too concerned but not sure if anyone else is having the same problem or heard of it before? Thanks for the help.