TMCL uses 64x microstepping
To read the current microstepping rate
for a given axis
use this command:
GAP 140, 0, 0
This example fetches the paraemter #140 "microstep resolution"
for axis 0.
In your case the distance of 15000 in full steps would mean: 730.5mm
At natural for TMCM110 16x microstepping
And at the default 64x
Note that at an unnaturally big microstepping rate for a given module, not every microstep actually produces a motion. Also the motion is slightly irregular even at natural microstepping
Another cause for wrong position would be missed steps
Wrong speed or acceleration might cause a stall. Some stalls are very prompt - just a few steps.
You may no actually notice it until you arrive to destination.
Please read a fundamental discussion about these and other issues here: