Each one of us went through the process of dialing in their X-Carve, so we understand just how frustrated you are. There's a good group of people in this forum that jump in and help whenever they can, and Inventables goes above and beyond to take care of their customers.
If you can give us some more information, we may be able to help figure this out. Here's a list of things that would help us out.
-What feed and speed?
-What type of wood?
-What method do you use for belt tension, and what is belt tension set at?
-Is there any wear on the edge of the belts, like you'd get from misaligned rollers?
-Is there any debris collected in the belt teeth or the pulley teeth?
-What other physical troubleshooting have you done?
-Since it happened in Easel, can you share the project link?
-Since it also happened in other programs, can you share the files?
OTHER (from photo above)
-What direction was it cutting in for the photo above (clockwise or counterclockwise)?
-Are the inner circles supposed to be offset?
-Of the 4 circles, what order were they cut in?
-Is the cut path any thicker than it should be?
-Did you notice any odd sounds while cutting?
-Did you notice any odd stopping while cutting?
I know it's a lot of questions, and I'm sure others will have more, but having this information will allow those of us with some experience to be able to come up with some other suggestions.