Welcome to the forum, Djjmaddox!
Maybe a little over half of the Spyderco lockbacks I have show some degree of up-and-down play. It's a tolerance issue and it's not a big deal.
If anything, a small amount of play would probably make the lock stronger, as it would be less likely to fail if something gets into the mechanism; like pocket lint, dirt, or food. The blade play actually disappears over time with some lockbacks, because crud from your pocket builds up in the notch in the tang and helps the surfaces mate better.
If there's, like, a LOT of play, then I'd worry, but a tiny amount is pretty normal. You might want to spine whack test it and do a little static load test to make sure the lock is holding.
Play is just normal on lockbacks though, and not on linerlocks. Even a tiny bit of up-and-down play on linerlocks is unacceptable, and a pretty clear sign that the lock will fail.