If history is any guide ...the Amtrak problems have just begun and both Amtrak and Bombardier should have known better. The Turbo train (running between Montreal and Windsor, circa1980) was pulled off the tracks for just this kind of problem ~20 years ago.
There is likely no problem in the train sets; I believe that in due course it will be found that a lack of rigidity in the track bed and track width variance are the culprits to the cracking problems that now plague the companies. Neither cast iron nor stainless steel take well to fatigue. JMHO
Good luck to all