Do note, that any "satellite trains" you see are from freshly launched satellites. The "trains" are from still relatively densely clumped satellites that are still separating from each other. After they separate, they re-orient which makes them almost invisible from the ground. You need long camera exposures or a telescope to see them at this point. They then start gradually raising their orbits to a parking orbit. After they reach a parking orbit they begin to drift the plane of their orbit so as to separate a single launch's satellites into multiple different planes, after which they then raise their orbits again into the operational orbit.