Originally Posted by
Leisesturm
So I completely missed that this is an electric assist bike! I thought PAS was an incorrect naming of IPS. Why wouldn't the electric hub not be a person of interest?! I would LOVE to be wrong, but I doubt very much that the rear hub is the problem.
As the o.p. said previously
"We've eliminated the PAS system, including switching back to the original front wheel, same results." So they have already ruled out the electric (front drive) hub.