I have been having problems with running my cnc router .

I have been having problems with running my cnc router . It will follow the pattern set by vectric, but halfway through it will go to a different spot and do the rest of the program. Chilipeppr says it is doing the right thing, but the machine messes up. Is it within chilipeppr, my machine where do I start? It has been running fine until now ,but the programs I put in will not work

tinyG or GRBL?
Is this a new design (job), or one that has run properly in the past?

I had similar problems in the past, I narrowed my issue down to stepper motor drivers “losing steps” due to heating. Reducing feed and pass depth resolved the issue. You might want to try that first.

My cnc router is belt driven and I had a similar issue when one of my belts was loose. It was couple of mm off here and there

I am running tiny G. It seems to do it in bot x and y and when it finishes it goes back to home correctly. Some I have run before correctly, and some are new designs.

I use worm drives