I agree...
Why would a missile go over 2000 km up, but less than 500 km down range???
(Space shuttle used to cruise at around 500 km)
Probably a test for weight, might have had a concrete dummy payload to mimic their latest nuclear warhead, if they can get the altitude then all they need now is to adjust the trajectory, and extend it. This is it, now they know just how much more boost it requires to extend its range.
The next test i don’t think will be a test, it will be a live warhead, though they might detonate it out in the mid pacific, my guess is between Hawaii and the mainland.Or just south of the Aleutians.