I have encountered the same problem. My i3 Rex is from 2015 and has 90.000 km. Suddenly the engine made increasingly a noice which, after investigation by the dealer, turns out to be a baering failure inside the electric motor. They have seen this 1-2 a year according to the dealer.
A refurbished motor can be fitted at € 5600,-. I'm unsure if it's worth it considering the age and km of the vehicle. And, whats next? The Rex?.
Question: in the old days you could contnue driving with a broken bearing until the noice simply became too loud. What are the risks in doing so with the electric motor?