Usually if there is an anomally and it corrects itself it is not due to a machine problem, usually when that happens its software related.
Just a guess.................
I used to run into problems like this with Mach 3 but usually that didnt correct itself. Pathpilot has never had a miscue here.
mike sr
Do you have an automatic oiler? It could be the hydraulic force of the oiler pushing the saddle and table up during oiling, thus the cutter cutting deeper on one or two passes only.