Originally Posted by the_traveler
Perhaps, it is just a quirk! But it's to bad I have to lose a segment every time!

I experience this same quirk NYP-NWK quite often.

All trains stop in NWK. I can book NYP-EWR, or NWK-EWR, but not NYP-NWK-EWR on the same train. In fact the previously available train does not even show up as an option NYP-NWK when booking multi segments.