What is wrong with my RAMPS X clone move/accel?

The RAMPS X Clone as X1 works beautifully But I am having a strange problem: If you look at the code, there are two different parts. One is for a simple stepper move, and the other is for a simple acceleration. The simple move with X and clone X1 work. Simple Accel clone X1 does not. While X fulfills its command to move to the right side by a thousand steps, X1 does not: It moves 300 steps to the left (approximately) and then 700 steps to the right!

Can anyone find the bug?

The code link: https://gist.github.com/d333gs/dcf4f4124e640bd9d9b5ea50a662454d