2x and 3x Train Wheel Assemblies rotate around their center point freely rather than being restricted by the points of contact by the wheels. Most noticeable at higher speeds. Very annoying. They do not derail but they do not look like they're on the tracks.

How to reproduce:

Simply place a 2x or 3x Train Wheel Assembly in the editor, spawn it in on the rails, and push it around. It does not matter if it is attached to anything or not.