There were slipping problems with firmware < 1.0.8. Make sure you are up-to-date.
Also note that a lack of parallelism with the 1F axis will cause the slippage to increase between each piece. I draw a simple project in Fusion 360 to illustrate: a symmetrical piece, rotate it (a lot for illustration purposes) and cut the holes again. You can see that the slippage increases.
