Hope you can find something as I am lost why the DRV8825’s are not working. The odd thing is that the Z axis is fine and it’s only affecting X and Y.
I looked at the time setting to release the steppers which is default set to 60. I tried higher and 0 to disable it all together. No change.
The settings in the config is the same between using the 8825’s and 4988. I swapped one of the drivers around and still the same issue.
I found this out when I was performing a dry run and checking the torque on the steppers by hand, right after a move where it would switch to a part where only the Y axis would move the X deactivated and I was able to move freely. This explains why I sometimes had the mill bite into a deeper cut an just destroy the work.