Would check this and see if it's the issue.It could be the bolt that holds the strut mount to the shaft cause when you tighten it, it spins the shaft as well so you would have to hold the shaft with some vise grip pliers.but your camber plate is your strut mount now and the same thing applies. could be the 3 bolts on the camber plate up top not being tight enough.
yeah also notice how it only happens when you hit a bump/imperfection on the road. something is definitely looseWould check this and see if it's the issue.