That definitely looks like a tooth off a gear. If your gears are all ok, that may be from a previous gear set thst was replaced, and they just didn't clean the case out. Not sure on what size bearing is supposed to be in there. How loose is it?
It sounds like it's not going all the way into gear. I'd tear it apart and check things out like the bearings or any shims in there. I am not familiar with that trans, so not much help other than that.