Not sure where the fault lays

[magicniner]

Give a full example of a problem program?

[Chaz]

Yep, share the code. It sounds like a mixup of settings (G91.1 sets Incremental mode).

G90 & G91 Distance Mode
Interpretation of Mac code can be in one of two distance modes: absolute or incremental.

To go into absolute distance mode, program G90. In absolute distance mode, axis numbers (X, Y, Z, A, B, C) usually represent positions in terms of the currently active coordinate system. Any exceptions to that rule are described explicitly in this section describing G-codes.

To go into incremental distance mode, program G91. In incremental distance mode, axis numbers (X, Y, Z, A, B, C) usually represent increments from the current values of the numbers.

I and J numbers always represent increments, regardless of the distance mode setting. K numbers represent increments in all but one usage (the G87 boring cycle), where the meaning changes with distance mode.



You also want to be sure you are not mixing MM and Inch.