Get_current_position in pydexarm

I use pydexarm to track robot arm position.
I ran ↓ program.

1 from pydexarm2 import Dexarm2
2 import time
3
4 dexarm = Dexarm2(’/dev/ttyACM0’)
5 dexarm.set_acceleration(8000, 8000, 8000)
6 time.sleep(2)
7 pos = []
8 dexarm.move_to( 100, 300, 0)
9 dexarm.move_to( -100, 300, 0)
10 for i in range(10) :
11 pos.append(dexarm.get_current_position())
12 time.sleep(3)
13 for ite in pos :
14 print(ite)

And result is as below.

image

My expecation is that x position starts from near 100(this comes from 1st move_to in 8th line), but 1st line in result is -75.78.
-75.78 is near goal position(-100 in 2nd move_to in 9th line).

Could you teach me how to get robot arm position from near start position?
(I tried to change set_acceleration parameter, but it looks like no influence for get_current_position function.)