I have the same play in my KH 20. I beat the thing up a lot so im happy nothing worse has happened. I’ve toyed around with a lot of different tightenings of various bolts but nothing seems to work. As long as nothing gets worse (which it hasnt in over a year) I dont really mind the play. In fact, i dont even notice it anymore. Im so happy not to have any suzue crap anymore!!!
If you don’t figure out the problem, VERY SOON, I’d send it back for an exchange.
BTW, my first unicycyle (32 years ago) developed a horrible skip in the pedals. With each revolution, the pedals would free-fall forward about 1 1/2 inches as they went over the top. Made for some very interesting riding. When I got my cottered Schwinn in 1976, as a replacement for that old Sears and Roebuck trainer, I was in HEAVEN! --chirokid–