I would check it to see if it's loose on the spindle. If it is, I'd remove it and check it for damage. If it looks ok I'd put it back on, using a new nut and the torque specs, like the manual says.
If it doesn't look loose, I'd worry that the nut was overtorqued. I've seen impact wrenches that can torque over 400 lb-ft. If it was overtorqued, I don't think I would trust it.
Of course there's always the chance that the new hub was just defective. Maybe it would be best to try to exchange it for a new one first.