Kevin,
I would be surprised if it is a bad bearing this early on. Not saying it can't happen.
Until you break it down we would only be guessing. Are you 100% sure your spindle bolts haven't back out any? Did you use the 0.5mm washers between the grips and head? On occasion thicker ones are needed. 1mm spacer washers are available. Let me know if you need them. I would be more than happy to send you two. This would take up that 1mm of play you mentioned. Assuming nothing else is amiss.
Cheers
alan