And that's the point, they are testing a missile against targets at much higher orbits. 14A042 is pretty enormous for a mobile missile.
They are aiming to take out US missile target discrimination system, the weakest link in the new US missile defence system.
https://en.m.wikipedia.org/wiki/Space_Tracking_and_Surveilla...
Without target discrimination, the missile defence will be completely exhausted by decoys.
The American test in the 80s was comparable.