"This isn't the first time this has happened. I wish I could remember the other instance!"
When the Acela trainsets were originally delivered to Amtrak back around 2000, they were just a bit "too wide" to be allowed to run at "full tilt" (the cars of the trainsets tilt into curves as they go around them at speed).
Originally, tilting was cut out from the east end of the East River tunnels in New York to the west entrance of the Hudson River Tunnels in New Jersey.
Also, the tilting feature had to be cut out prior to entering Metro-North territory (New Rochelle NY to New Haven), again because of concerns for clearances between passing trains on curves.
I believe that all this got rectified in time, not sure exactly what they did. Might have required changes in curve alignments, or perhaps changes to the train's operating software...